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ORNL/TM-2014/57

Sustainable Transportation Program

2013 Annual Report

Compiled by

Kathi H. Vaughan

for

Ronald L. Graves, Director

ORNL Sustainable Transportation Program

Date Published: May 2014

Prepared by

OAK RIDGE NATIONAL LABORATORY

Oak Ridge, Tennessee 37831-6283

managed by

UT-BATTELLE, LLC

for the

U.S. DEPARTMENT OF ENERGY

under contract DE-AC05-00OR22725

2013 Annual Report Contents

ORNL Sustainable Transportation Program iii

Table of Contents

Introduction ............................................................................................................................................1

Program Metrics.............................................................................................................................3

Funding...................................................................................................................................3

Industry Impact.......................................................................................................................4

Patents and Invention Disclosures..........................................................................................6

Staff Awards and Honors........................................................................................................8

Infrastructure and Facility Investments ..................................................................................9

Bioenergy Technologies R&D Highlights ...........................................................................................13

Clean Cookstove Reduces Toxic Emissions from Biomass.........................................................13

ORNL Examines the Sustainability of Silvicultural Practices for Bioenergy..............................14

Sun Grant Regional Feedstock Partnership ..................................................................................16

Evaluation of Heavy and Overweight Commercial Vehicles.......................................................18

Department of Transportation R&D Highlights...................................................................................18

Intelligent Transportation Systems Asset Viewer ........................................................................19

ORNL Helps Federal Motor Carrier Safety Administration Assess Funding ..............................20

ORNL Analysts Work to Strengthen Motorcoach Safety ............................................................22

Fuel Cell Technologies R&D Highlights.............................................................................................24

Advanced Microscopy Reveals Details of Proton Exchange Membranes....................................24

Melt-spun PAN Fibers for Gas Storage Tanks Meet Program Milestone ....................................25

Market Prospects of Fuel Cell Plug-in Hybrid Electric Vehicles.................................................27

Vehicle Technologies R&D Highlights................................................................................................29

Analysis................................................................................................................................................29

My Plug-in Hybrid Calculator @www.fueleconomy.gov............................................................29

Impact of On-Road Wireless Charging on the Electric Vehicle Market ......................................31

Costs of Oil Dependence to the US Economy..............................................................................34

Learning-from-History Feature of the MA3T Model...................................................................36

Optimal Market Mix of BEV Ranges for US Consumers............................................................37

Combustion Engines and Fuels............................................................................................................40

Benefits of High-Octane Ethanol Blends .....................................................................................40

EGR Probe Applications Enable Engine Performance Advances................................................41

High-Efficiency Clean Combustion in Light-Duty Diesel Engines .............................................43

Novel Bimetallic Catalysts Improve Low-Temperature Oxidation..............................................44

First Systematic Study of GDI PM Size, Shape, and Composition..............................................46

New Method Assesses Engine Efficiency Opportunities.............................................................47

Impacts of Biodiesel Impurities on Emissions Control System ...................................................48

Energy Storage .....................................................................................................................................51

ORNL Produces Lithium-Ion Battery Electrode via Water-Based Process.................................51

Computer-Aided Engineering for Batteries..................................................................................52

Studying High-Voltage Battery Cathodes for Electric and Hybrid Vehicles...............................53

New Solid State Sulfur-Based Battery .........................................................................................56

Lightweight Materials ..........................................................................................................................58

Online Weld Quality Monitor and Control with Infrared Thermography ....................................58

Improving Fatigue Performance of AHSS Welds........................................................................59

Austenite-Ferrite Transformation Details in Carbon Steels .........................................................61

IR Heat Treatment and Residual Stress Characterization of Bimetallic Joints ............................62

ORNL Commissions Carbon Fiber Technology Facility .............................................................64
Contents 2013 Annual Report

iv ORNL Sustainable Transportation Program

Advanced Oxidative Stabilization of Carbon Fiber Precursors ................................................... 66

Understanding Protective Film Formation by Magnesium Alloys in Automotive 

Applications................................................................................................................................. 68

Power Electronics and Electric Motors................................................................................................ 71

10 kW Wide Bandgap Device-Based Inverter............................................................................. 71

Advanced All-SiC Automotive Power Electronics Module......................................................... 72

Development of Low-Loss Motor Lamination Steel ................................................................... 74

Multiple Isolated Flux Path Switched Reluctance Motor ............................................................ 75

Propulsion Materials............................................................................................................................ 77

Studies Confirm Catalytically Active Single Platinum Atoms.................................................... 77

Electron Microscopy for Characterization of Catalyst Microstructure ........................................ 78

Computational Modeling Assists Development of New Valve Alloys........................................ 80

Thermally Conductive Epoxy Molding Compound..................................................................... 81

Surface Micro-Engineering Lowers Friction to Improve Fuel Economy .................................... 83

Vehicle Systems................................................................................................................................... 85

Wireless Charging for Electric Vehicles...................................................................................... 85

Vehicle Systems Integration Laboratory Advances Powertrain Research................................... 87
Introduction

ORNL Sustainable Transportation Program 1

Introduction Oak Ridge National Laboratory’s (ORNL’s) Sustainable Transportation Program (STP) performs research and development (R&D) leading to new vehicle and transportation system 

technologies. The program’s R&D portfolio includes advanced combustion engines, advanced materials, alternative fuels, efficient vehicle components, intelligent transportation 

systems and operations, transportation electrification, and vehicle systems integration.

ORNL also provides data and analysis to guide policies and decisions of the Department of 

Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) and the Department of Transportation (DOT). 

The focus of Sustainable Transportation is clean, efficient, intelligent paths to reducing petroleum consumption and vehicle emissions, and to replacing imported petroleum with affordable, diverse domestic fuels to revitalize the US economy and improve US energy security. Millions of vehicles on US roadways are more durable and more efficient because of 

materials technologies developed at ORNL, and government agencies and consumers make 

transportation decisions every day using data collected and analyzed by ORNL.

The Program’s primary support comes from DOE EERE through three technology development offices: Vehicle Technologies, Fuel Cell Technologies, and Bioenergy Technologies. 

Support also comes from DOT, other federal agencies, and the private sector. ORNL supports the US DRIVE (Driving Research and Innovation for Vehicle efficiency and Energy 

sustainability) and the 21st Century Truck government–industry partnerships, as well as 

DOE’s EV Everywhere Grand Challenge and other sustainable transportation efforts. 

The Sustainable Transportation research program pursues an “all of the above” strategy that 

incorporates 

• accelerating widespread use of electric vehicles powered by both batteries and fuel cells

• increasing the efficiency of all types of vehicles though lighter materials and advanced 

combustion and power train technologies

• enabling widespread use of cleaner fuels such as biofuels and natural gas

• collecting, analyzing, and disseminating data to support efficient commercial fleet operation, intelligent systems, congestion management, and informed decision-making

These efforts are directed toward attaining

• efficient, safe, affordable vehicles for passengers and freight

• domestic production of transportation fuel

• reduction of the environmental impacts of transportation

• predictability and reliability in transport scheduling

Transportation is a key factor in the energy and environmental future of the United States. 

Highway transportation (light-, medium-, and heavy-duty vehicles) accounted for more than 

25% of US greenhouse gas emissions 1 and about 60% of US petroleum consumption in 2011.2

Although energy use by light-duty passenger vehicles is projected to decline by about 20% by 

2040—largely as a result of more stringent greenhouse gas and corporate average fuel econo-

 1 S. C. Davis, S. W. Diegel, and R. G. Boundy, Transportation Energy Data Book: Edition 32, ORNL-6989, Table 11.4, 2013.

2 Ibid, Table 1.17.
Introduction 2013 Annual Report

2 ORNL Sustainable Transportation Program

my regulations—light commercial trucks and heavy trucks are projected to use almost 45%

more energy in 2040 than in 2011.3 A sustainable transportation system that increases efficiency, cuts pollution associated with vehicle use and production, relies more on renewable fuels, 

and increases highway safety is an indispensable part of a sustainable future.

In support of the Vehicle Technologies Office (VTO) in FY 2013, ORNL researchers implemented a user-friendly online calculator that supplies personalized estimates of energy costs 

and gas station visits for a specific plug-in hybrid electric vehicle (EV); manufactured a lithium-ion battery using a process that replaces a toxic, expensive, chemical with deionized 

water; determined that blending as much as 30% ethanol with regular gasoline may improve fuel efficiency in conventional gasoline vehicles; developed cost-effective nickel-based 

alloys for valves in high-temperature automotive applications, using a materials-by-design 

approach incorporating computation and experiment; developed a robust, highly efficient 

10 kW wide-bandgap inverter for use in EVs; and completed the installation of several major pieces of test equipment in the Vehicle Systems Integration Laboratory, which can test 

conventional and hybrid powertrains for architectures ranging from light-duty vehicles to 

fully loaded Class 8 trucks.

An ORNL effort sponsored by the Bioenergy Technologies Office (BETO) is studying the 

impacts of short-rotation tree farming for bioenergy, examining the effects of intensive silviculture practices on watersheds. It is a collaboration with the US Forest Service and several 

universities. In concert with industrial and academic partners, ORNL produced a low-cost, 

highly efficient “clean cookstove” with a metal combustor that is more durable against corrosion than earlier versions of the stove. The efficient, affordable stove dramatically reduces 

harmful combustion gases and fuel use compared with the traditional biomass-fueled fires 

and stoves that are widely used in the developing world. The Regional Feedstock Partnership assessed biomass crop yields across the country to gather regional crop productivity 

data for models and databases supporting biomass feedstock supply and logistics systems.

In research supporting the Fuel Cell Technologies Office (FCTO), ORNL researchers produced melt-spun carbon fibers that met a major go/no-go performance milestone. Carbon 

fiber composites are a prime candidate material for hydrogen storage tanks if they can satisfy cost and performance targets. The melt-spinning approach promises to be much less costly than the process currently used, and the ORNL fibers demonstrated the required tensile 

strength and modulus of elasticity. In another project, materials scientists established analytical methods for using advanced electron microscopy and spectroscopy to characterize fuel 

cell membrane electrode assemblies so that materials can be selected or modified to improve 

membrane performance. The techniques were used to reveal the mechanisms of carbon corrosion. A study of market prospects for fuel cell plug-in hybrid EVs conducted using 

ORNL’s MA3T model found that the vehicles have the potential to succeed in the marketplace in both the near and the long term.

Research sponsored by DOT included the launch of the Intelligent Transportation Systems 

(ITS) Asset Viewer, an online application that uses visual mapping technology to identify 

the locations of ITS transportation tools such as message boards, traffic sensors, and road 

 3 US Energy Information Administration, Annual Energy Outlook 2013 with Projections to 2040, US Department of 

Energy, Washington, D.C., Table A7, 2013.
2013 Annual Report Introduction

ORNL Sustainable Transportation Program 3

weather information systems. Data from the system will enable DOT to analyze the impacts

of ITS technologies. ORNL analysts worked with the Federal Motor Carrier Safety Administration to help identify policy and process weaknesses related to motorcoach safety and 

suggest needed changes. And ORNL assisted the Federal Motor Carrier Safety Administration in evaluating its formulae for granting financial assistance to the states. 

Highlights of these and other STP R&D efforts begin on page 13.

Program Metrics

Funding

The STP received $78M in new budget funding in FY 2013. Approximately $23M, or 30%, is 

funding for projects that were competitively awarded by DOE EERE via Funding Opportunity Announcements. DOE VTO remains the largest sponsor of the ORNL program. DOT 

and DOE FCTO budgets remained stable in FY 2013, while funding from the DOE BETO

grew compared with FY 2012. 

$14.4

$6.1

$49.4

$6.4

$1.7

New FY 2013 Funding by Sponsor ($M)

DOE Bioenergy Technologies

DOE Fuel Cell Technologies

DOE Vehicle Technologies

Department of Transportation

Industry and Others

Program funding provided significant support for more than 165 scientific and technical 

staff in 10 technical divisions, reflecting the broad, multidisciplinary character of the ORNL 

program. The STP team leaders are shown in the following organization chart.
Introduction 2013 Annual Report

4 ORNL Sustainable Transportation Program

Industry Impact

ORNL’s STP conducts the vast majority of its R&D in collaboration with industry so that 

pathways to commercialization are built into projects from the beginning. Industry partnerships are carried out through a variety of mechanisms, including Cooperative Research and 

Development Agreements (CRADAs), work for others (WFO) agreements, technology licensing, User Facility Agreements, and informal collaborations and information exchanges 

at technical conferences and workshops. 

CRADAs

STP researchers supported 17 CRADAs in FY 2013 with 13 different companies, developing 

an array of technologies including new materials for high-efficiency engines, advanced 

combustion regimes, alternative fuels, and hybrid and EV components and systems. In 

FY 2013, our industry partners contributed about $7M in materials and services toward 

these efforts, nearly half of the total funding for the projects. 

WFO Agreements

ORNL worked with 16 industrial companies, 14 federal and state government entities, and 4 

universities under 52 separate WFO agreements in FY 2013. In total, these agreements were 

valued at about $8M. 

Technology Licensing

US-based all-electric vehicle manufacturing startup Arcimoto has exclusively licensed a 

combination of three ORNL technologies—an innovative ac-dc inverter, a battery system 
2013 Annual Report Introduction 

ORNL Sustainable Transportation Program 5 

charger, and a dc-dc inverter—to enable Arcimoto to build a drivetrain that eliminates the 

need for a stand-alone external charger. The technologies also let the system operate at 

higher temperatures by significantly reducing undesirable motor torque ripple. The 

Arcimoto–ORNL partnership was the focus of an article titled “A Promising New Electric 

Car Is on the Horizon” that appeared in Innovation Magazine Online. 

User FacilityAgreements

Four nonproprietary user projects were approved for the National Transportation Research 

Center (NTRC). 

Los Alamos National Laboratory—Robust Nitrogen Oxide/Ammonia Sensors for Vehicle On-Board 

Emissions Control

The goal of this project is to develop robust electrochemical sensors capable of reliably detecting 1–500 ppm nitrogen oxides and 1–50 ppm ammonia in a vehicle exhaust stream. The 

Los Alamos National Laboratory (LANL) team completed two sets of experiments with 

their sensor on the NTRC’s unique engine research platform. Results were very promising, 

with LANL’s sensor demonstrating the ability to distinguish different pollutant gases in real 

exhaust. Results were presented during a Cross-Cut Lean Exhaust Emissions Reduction 

Simulations (CLEERS) Focus Group teleconference, and further presentations and publications are planned.

Texas A&M University—Characterization of Surface Area and Kinetic Oxidation of Particulate 

Matter from Advanced Gasoline Direct Injection Engine Technologies

Texas A&M University seeks to characterize the surface area and oxidation kinetics of particulate matter (PM) or “soot” generated from an advanced gasoline direct injection (GDI)

engine to better understand how PM can be controlled in aftertreatment devices. Texas 

A&M collected PM from the NTRC GDI engine platform during the combustion of alternative fuels and is analyzing the nature of the PM as it relates to oxidation processes that enable control of the PM in emission control systems.

Pacific Northwest National Laboratory—Detailed Characterization of PM from Advanced Combustion Engines

Researchers from Pacific Northwest National Laboratory (PNNL) brought the Single Particle Laser Ablation Time-of-Flight Mass Spectrometer (SPLAT) to the NTRC for a two-week 

sampling campaign. SPLAT is able to physically and chemically characterize individual particles, thus giving a complete picture of the particle emissions from an engine. The combination of SPLAT and the advanced, unique engine platforms at the NTRC produced an unprecedented examination of exhaust emissions from lean GDI, partially premixed charge 

gasoline compression ignition, and reactivity-controlled compression ignition under a variety of light-duty operating conditions. The studies will provide a better understanding of 

how to control the unique PM from these fuel-efficient engine concepts. Preliminary results 

were presented to the U.S. DRIVE4 Advanced Combustion and Emissions Control Tech 

Team, and ongoing data analysis will yield more results for inclusion in presentations and 

publications.

 

4 U.S. DRIVE is a cooperative partnership between DOE and industry to accelerate the development of clean, advanced, 

energy-efficient technologies for cars and light trucks and the infrastructure needed to support their widespread use. 
Introduction 2013 Annual Report

6 ORNL Sustainable Transportation Program

3M Company—Thermal Insulation in Automotive Exhaust Systems for Advanced Combustion 

Engines

3M Company has a specific interest in the use of insulating materials for thermal management to control emissions. The user project was approved in FY 2013 and scheduled for 

January 2014, but an engine water coolant line failure occurred during uncommon freezing 

temperatures. The campaign was delayed to a more suitable time for the engine platform of 

interest and is now planned for the summer of 2014.

Patents and Invention Disclosures

ORNL research sponsored by DOE’s VTO, FCTO, and BETO resulted in 40 invention disclosures and 11 patent applications. Twelve patents were issued based on earlier filings, as 

shown in Table 1. Patent applications filed in FY 2013 are shown in Table 2.

Table 1. Patents awarded during FY 2013

Inventor(s) Title Number Sponsoring 

EERE Office

David Joseph Singh Alkaline earth filled nickel 

skutterudite antimonide 

thermoelectrics

8,487,178 B2 VTO

Jy-An Wang, Zhili Feng, Lawrence 

M. Anovitz, and Kenneth C. Liu

Apparatus and method for 

fatigue testing

of a material specimen in a 

high-pressure 

fluid environment

8,453,515 B2 FCTO

Chaitanya K. Narula and 

Claus Daniel

Solid lithium ion conducting 

electrolytes and methods of 

preparation

8,449,790 B2 VTO

Govindarajan Muralidharan, 

Yukinori Yamamoto, and 

Michael P. Brady

Cast alumina forming austenitic stainless steel8,431,072 B2 VTO

Gui Jia Su Electrical motor/generator 

drive apparatus and method

8,373,372 B2 VTO

John S. Hsu Substantially parallel flux uncluttered rotor machines8,330,319 B2 VTO

John S. Hsu Flux control and onehundred and eighty degree 

core systems

8,319,464 B2 VTO

James E. Parks and 

William P. Partridge

Optical backscatter probe 

for sensing particulate 

in a combustion gas stream

8,451,444 VTO
2013 Annual Report Introduction

ORNL Sustainable Transportation Program 7

Table 1. Patents awarded during FY 2013 (continued)

Inventor(s) Title Number Sponsoring 

EERE Office

Roman I. Pankiw, Govindarajan 

Muralidharan, Vinod Kumar Sikka, 

and Philip J. Maziasz

Cast heat-resistant austenitic 

steel with improved temperature creep properties and 

balanced 

alloying element additions 

and methodology 

for development of the 

same

8,318,844 VTO

Matthew B. Scudiere Off-resonance frequency 

operation for power transfer 

in a loosely coupled air core 

transformer

8,310,202 VTO

John S. Hsu Brushless machine having 

ferromagnetic side plates 

and side magnets

8,294,321 VTO

James P. Szybist and 

James C. Conklin

Highly efficient 6-stroke engine cycle with water injection8,291,872 VTO

Table 2. Patent applications filed during FY 2013

Inventor(s) Title Number Sponsoring 

EERE Office

Jy-An Wang, Zhili Feng, and 

Wei Zhang

Hydrogen storage container 13/940,567 FCTO

Amit K. Naskar, Felix L. Paulauskas, 

Claude C. Eberle, Christopher J. 

Janke, and Charles D. Warren

Sulfonated polyolefin-based 

flame retardant material

61/762,489 VTO

William P. Partridge and James E. 

Parks II

EGR distribution and fluctuation probe based on CO2

measurements

13/912,462 VTO

Amit K. Naskar Controlled chemical stabilization of polyvinyl precursor 

fiber, and high strength carbon fiber produced therefrom

13/860,188 VTO

Felix L. Paulauskas Atmospheric pressure plasma processing of polymeric 

materials using close proximity indirect exposure

13/680,406 VTO

Michael D. Kass, Shean P. Huff, 

Samuel A. Lewis Sr., Timothy J. Theiss, 

Steven J. Pawel, and 

Christopher J. Janke

System for determining biofuel concentration13/939,479 VTO
Introduction 2013 Annual Report

8 ORNL Sustainable Transportation Program

Table 2. Patent applications filed during FY 2013 (continued)

Inventor(s) Title Number Sponsoring 

EERE Office

Chaitanya K. Narula and 

Claus Daniel

Solid lithium ion conducting 

electrolytes and methods of 

preparation 

13/886,542 VTO

Madhu S. Chinthavali Gas cooled traction drive 

inverter

14/016,327 VTO

Sreekanth Pannala, Chaitanya K. 

Narula, Raymond R. Unocic, Nancy 

J. Dudney, and Jagjit Nanda

High energy density secondary lithium batteries13/651,322 VTO

Nancy J. Dudney Lithium-conducting sulfur 

compound cathode for lithium-sulfur batteries

13/974,854 VTO

Timothy A. Burress and Curtis W. Ayers Reluctance motor 13/944,731 VTO

Staff Awards and Honors

Program research staff members were honored with an array of awards and professional 

recognitions, reflecting meaningful contributions to research, technology development, and 

service to professional societies. A selection of the most significant is shown in Table 3. 

Table 3. Significant awards and professional honors received by STP researchers

ORNL Awardee Name(s) Name/Type of Award

Scott Curran R&D Technology Award from the DOE Vehicle 

Technologies Office

Best Presentation at the 2012 Fall Technical Conference from the American Society of Mechanical Engineers Internal Combustion Engine Division

Virginia H. Dale Distinguished Landscape Ecologist Award from the 

U.S. Regional Association of the International Association for Landscape Ecology

Claus Daniel “40 Under 40” award from the Greater Knoxville Business Journal

Claus Daniel, Curt Maxey, David 

Wood, Beth Armstrong, Jianlin Li, Amit 

Shyam, Harry Meyer, Ralph Dinwiddie, 

Wally Porter, Cristian Contescu, Edgar 

Lara-Curzio, Hsin Wang, Rosa Trejo,

Jane Howe

R&D100 Award for Symmetrix HPX-F

C. Stuart Daw Fellow, American Institute of Chemical Engineers

Nancy J. Dudney Fellow, Electrochemical Society
2013 Annual Report Introduction

ORNL Sustainable Transportation Program 9

Table 3. Significant awards and professional honors received by STP researchers (continued)

ORNL Awardee Name(s) Name/Type of Award

Zhili Feng Fellow, American Welding Society

Ronald L. Graves R&D Technology Award from the DOE Vehicle Technologies Office

David L. Greene Distinguished Career Service Award from the DOE Fuel 

Cell Technologies Office

David L. Greene Roy W. Crum Distinguished Service Award from the 

Transportation Research Board of the National Academies

Janet Hopson R&D Technology Award from the DOE Vehicle Technologies Office

Hua-Tay Lin Honor Medal of Aurel Stodola, Slovak Academy of 

Sciences

Hua-Tay Lin Distinguished Engineering Achievement Award from 

The Engineers’ Council

Hua-Tay Lin Appointment to the Advisory Board of the World 

Academy of Ceramics

Philip J. Maziasz William Hunt Eisenman Award from ASM International 

for “outstanding success in the development of new 

heat-resistant stainless steel and alloys with significant 

commercial impact in advanced transportation, coalfired generation, and nuclear power generation” 

Karren L. More R&D Technology Award from the DOE Fuel Cell Technologies Office

Mitchell Olszewski North Atlantic Treaty Organization Applied Vehicle 

Technology Fall 2012 Panel Excellence Award

William P. Partridge, James E. Parks II, 

David Sims

R&D100 Award for Da Vinci Fuel-in-Oil (DAFIOTM) 

Measurement System

Shahabaddine Sokhansanj Standards Developer Award from the American Society of Agricultural and Biological Engineers

Fellow, Engineers Canada

John M. Storey Fellow, SAE International

Leon Tolbert Fellow, IEEE

Todd J. Toops, Michael J. Lance Researchers of the Year from 2012 Biodiesel Technical 

Workshop

Robert M. Wagner Fellow, SAE International

Brian H. West Fellow, SAE International

Infrastructure and Facility Investments

Battery Manufacturing Facility (BMF). The BMF demonstrated double-sided electrode 

manufacturing of LiNi1/3Mn1/3Co1/3O2 cathodes. This success significantly enhanced the 

BMF’s capability in electrode manufacturing and completed an industry-ready pilot scale in 

spring 2013. The BMF also demonstrated DOE’s first fully water-processed lithium-ion bat-
Introduction 2013 Annual Report

10 ORNL Sustainable Transportation Program

tery, reducing pack cost by 15–20%, and it won an R&D100 Award for a new separator 

technology developed through an industrial collaboration with Porous Power Technologies.

Carbon Fiber Technology Facility. All key performance parameters committed to DOE in 

the Project Execution Plan were proved. Several successful conversion runs prior to commissioning produced carbon fibers in 12K, 24K, and 48K tow format. A ribbon cutting ceremony was held in March 2013. The facility includes a nearly 400 foot long line for producing 

carbon fiber in pre-commercial quantities, and it will explore more efficient and less costly 

carbon fiber production methods in an effort to bring down the cost of carbon fiber for vehicle applications. 

Commercial Motor Vehicle Roadside Technology Consortium (CMVRTC). ORNL proposed and DOT approved expansion of the Consortium (formerly “Corridor”; the name was 

changed October 1, 2013) to include 30 sites in 5 states and more than 2,400 miles of interstate highway. Sites in Alabama, Georgia, Kentucky, and North Carolina are now a part of 

this real-world test bed for commercial vehicle operation. The first project to take advantage 

of the expanded facility is the Wireless Roadside Inspection Field Operational Test. 

Energy Storage. ORNL built a pinch simulation testing system used at the Naval Surface 

Warfare Center in Carderock, Maryland, to conduct internal short-circuit testing of 18 and 

25 ampere-hour lithium-ion cells. The tests were successful in distinguishing the safety factor of lithium-ion cells with different chemistries and capacities.

Fuels, Engines, and Emissions Research Center (FEERC). FEERC is partnering with Ford 

Motor Company to investigate the potential for the use of high-octane fuels to enable greater fuel economy. Ford provided FEERC with a state-of-the-art 1.6 liter Ecoboost® 4-cylinder 

engine to support the work. ORNL’s work will focus on increasing the compression ratio of 

the engine to improve low-load fuel economy, while using the increased anti-knock properties of high-octane fuels to reduce fuel consumption due to knock avoidance at high-load 

conditions. 

Lightweight Materials Research. ORNL researchers designed an alternate fixture for holding magnesium sheet during dome testing. The new design, which uses a ring-in-groove 

mechanism, is more effective at clamping and holding samples to prevent draw-in of the 

sheet during dome testing. The dome test simulates the common failure strain states in sheet 

metal forming processes. 

Performance-based Brake Tester (PBBT). A newly refurbished PBBT was received for use 

in the CMVRTC. The refurbishment includes a new generator set and new trailer for mobility. Tennessee Highway Patrol officers were trained in use of the equipment by the equipment vendor and ORNL. The new PBBT supports a number of ORNL-led research efforts 

within the CMVRTC, including the Brake Causation and Abatement Study, the Infraredbased Selection System, and Vehicle Out-of-Service Data Collection. There are now five 

fixed and portable PBBTs in use by the Tennessee Highway Patrol.

Vehicle Systems Integration (VSI) Laboratory. The AVL powertrain dynamometer test 

system demonstrated full functionality using a conventional Class 8 heavy-duty powertrain 

making up a Cummins 15L ISX engine. The hardware-in-the-loop system was commissioned for both engine- and powertrain-in-the-loop configurations. Both conventional and 
2013 Annual Report Introduction

ORNL Sustainable Transportation Program 11

hybrid powertrain architectures were successfully demonstrated. Two sets of emission analyzers were commissioned to measure raw, engine-out emissions and post-aftertreatment 

(tailpipe) emissions. The AVL eStorage system (battery emulator) has been installed, and an 

AVL high-speed dynamometer and a modular bed plate have been ordered for the VSI 

component test cell. The bed plate and dynamometer provide features to support two separate, simultaneous experimental setups. Commissioning of the component test cell and the 

battery emulator is planned for FY 2014.

Bioenergy Technologies R&D Highlights

ORNL Sustainable Transportation Program 13

Clean Cookstove Reduces Toxic Emissions Bioenergy Technologies R&D Highlights from Biomass

Contact: Mike Brady, bradymp@ornl.gov, 865-574-5153

Half of the world’s population cook their food by burning biomass fuel over open fires or 

rudimentary, inefficient stoves. The toxic emissions produced cause more than 4 million 

premature deaths a year and account for 20% of the world’s black carbon, contributing 

significantly to regional and global climate change. ORNL is part of a partnership that has 

developed and continues to improve on a low-cost, highly efficient cookstove to help solve 

this complex problem.

ORNL has worked with Envirofit International (EI) and Colorado State University (CSU) 

since 2008 to develop metallic materials for use as combustor components in clean 

cookstoves for the developing world. ORNL researchers identified suitable commercially 

available, low-cost metal combustor alloys that are durable in the harsh operating 

environment of the combustor, at sufficiently low cost to permit widespread adoption. The 

combustor component in the EI design must resist temperatures up to 800–900°C (1,470–

1,650°F) in the presence of aggressive corrosive compounds from varied biomass fuels. 

ORNL also pursued ways of optimizing the specification of combustor alloy composition, 

impurity level, and heat treatment for durability at the lowest possible alloy cost. 

The key technological aspect of this cookstove is a combustor chamber (patent pending by 

EI, CSU, and ORNL) with design features, geometry, and materials to enable cleaner, more 

efficient combustion. Compared with the ceramic combustor used in the previous 

generation of EI cookstoves, the metal combustor is more mechanically robust and better 

able to withstand transportation and delivery to remote locations without component 

breakage. The use of a metal for the combustor also permits the use of a thin orifice plate, 

which further reduces emissions.

Envirofit G-3300 clean cookstove using low-cost ironbase alloy combustor (photo courtesy of Envirofit).
Bioenergy Technologies R&D Highlights 2013 Annual Report

14 ORNL Sustainable Transportation Program

The resulting EI G-3300 clean cookstove is a low-cost, low-emission alternative to cooking 

methods now prevalent in developing countries. It reduces smoke and harmful gases by 

80%, fuel use by 60%, and cooking time by 50% compared with traditional cooking fires and 

stoves. EI has integrated the core metal combustor technology developed for the G-3300 

across six models of wood and charcoal stoves. To date EI has sold more than 700,000 

cookstove units in the developing world, most of which use the metal combustor 

component. 

The continuing ORNL-EI-CSU collaboration is devoted to improving understanding of 

combustion and heat transfer in cookstove metallic combustors to guide cookstove design 

and improve materials durability for a wide range of biomass feedstocks. Key activities will 

include public dissemination of corrosion and durability findings as a function of alloy type 

and biomass feedstock and evaluation of optimized alloys and/or coatings for a targeted 

40% durability improvement over existing materials.

ORNL Examines the Sustainability of Silvicultural Practices for Bioenergy

Contact: Natalie Griffiths, griffithsna@ornl.gov, 865-576-3457

An important goal of bioenergy is environmentally sustainable feedstock production with 

minimal impact on soil and water resources. ORNL is leading an effort to evaluate the 

sustainability of high-intensity, short-rotation forestry for bioenergy that involves 

mechanical planting and annual or biannual fertilization and herbicide application. 

The study is using both a watershed-scale experiment (at three watersheds in South 

Carolina) and a watershed modeling approach. Baseline water and soil data were collected 

from all three watersheds for two years (2010–2012). Starting in spring 2012, more than 40% 

of two watersheds was harvested, prepared for planting, and then planted with loblolly 

pine seedlings (winter 2013). Intensive silviculture activities (weed control and fertilization) 

necessary to achieve high yields are occurring in the two treatment watersheds (2013–2018). 

The third watershed is not manipulated and serves as a reference to account for variations 

in hydrology, water quality, and soil quality over time. Indicators of environmental 

sustainability are measured across the watersheds to assess whether short-rotation pine 

practices affect water and soil resources and whether current forestry best management 

practices are adequate for more intensive silviculture.

Hydrology and water quality data are also used to parameterize watershed-scale 

hydrological models. The goal of the modeling effort is to scale up the watershed 

observations to determine how woody feedstocks for bioenergy will affect hydrology and 

water quality at larger temporal and spatial scales.

To date, the project has been successful in characterizing baseline water quality and 

quantity in the three watersheds and has begun to examine short-term effects of the 

silviculture practices. Baseline water quality and hydrology data have been critical in 

determining the dominant flow paths in the watersheds, helping infer the fate of fertilizers 

and herbicides applied. Baseline measurements, experiments, and modeling together show

that overland and lateral flows through soils are rare, suggesting that upland areas and

streams are rarely connected hydrologically. Groundwater and stream flow observations,
2013 Annual Report Bioenergy Technologies R&D Highlights

ORNL Sustainable Transportation Program 15

Loblolly pine seedlings after planting in 2013.

coupled with isotopic and water chemistry data, show that riparian groundwater is a 

dominant source of stream flow. These results suggest that fertilizers and herbicides applied 

on the pine plantations in the upland areas are more likely to enter the groundwater than to 

be directly transported via lateral flow or overland flow to streams. These inferences from 

the baseline measurements and modeling efforts will be tested as the experiment proceeds.

This project is a collaboration between ORNL, the US Forest Service, the University of 

Georgia, Oregon State University, and the University of Saskatchewan.
Bioenergy Technologies R&D Highlights 2013 Annual Report

16 ORNL Sustainable Transportation Program



15NNO3 (‰)

-5 0 5 10 15

18

ONO3 (‰)

-20

0

20

40

60

80

100

Deep groundwater

Riparian groundwater

Stream water

Throughfall

Soil water

Watershed R

Dual isotope biplot of δ18O and δ15N of nitrate in various water 

pools measured in reference (unmanipulated) watershed in

the pre-treatment period. Overlap in the stable isotope 

signatures of nitrate in stream water (red triangles) and 

groundwater from the surrounding riparian zone (blue 

squares) suggests groundwater is the source of stream water 

nitrate. In contrast, nitrates in soil water (yellow triangles) and 

stream water have different stable isotope signatures, 

suggesting disconnect between upland areas and stream.

Presentations

1. N. A. Griffiths, P. J. Mulholland, C. R. Jackson, J. J. McDonnell, J. I. Blake, E. Du, J. Klaus, 

and M. H. Langholtz, “Biogeochemistry of forested watersheds in the Southeastern U.S. 

prior to conversion to short-rotation pine for bioenergy,” presented at American 

Geophysical Union Conference, San Francisco, December 3–7, 2012. 

2. K. B. Vache, C. R. Jackson, M. Bitew, J. Blake, J. J. McDonnell, and N. A. Griffiths, 

“Potential impacts of intensive cellulosic biofuel production on water quality and 

quantity in the Upper Coast Plain,” presented at American Geophysical Union 

Conference, San Francisco, December 9–13, 2013.

Sun Grant Regional Feedstock Partnership

Contact: Laurence Eaton, Oak Ridge National Laboratory, eatonlm@ornl.gov

The Sun Grant Initiative’s Regional Feedstock Partnership commenced in 2007 with the goal 

of supporting the commercialization of biomass and biotechnology to meet a billion-ton annual supply as envisioned in DOE’s 2005 Billion-ton Report. The partnership includes more 

than 100 feedstock field trials and regional resource assessments focused on agricultural residues (e.g., corn stover) and a suite of likely dedicated energy crops, including switchgrass. 
2013 Annual Report Bioenergy Technologies R&D Highlights

ORNL Sustainable Transportation Program 17

In 2013–2014, a series of meetings was held across the United States with each of six crop 

teams and the resource assessment team to review yield trials in order to map crop productivity nationally across all soils and climatic regions. The analysis contributes to data models 

within ORNL’s Bioenergy Knowledge Discovery Framework and the biomass chemical and 

physical characterization within the Idaho National Laboratory’s Biomass R&D Resource 

Library. Together, these data collections provide empirical support of feedstock supply and 

logistics systems. The temporal and spatial data for biomass yield and compositional traits 

support the advancement of efficient, cost-effective system designs for conversion of biomass to renewable fuels, biopower, and industrial bioproducts.

Switchgrass harvested at the Cornell trial of the Regional Feedstock Partnership (Source: 

North Central Sun Grant Center, http://ncsungrant.sdstate.org/)

Potential annual yield of lowland switchgrass varieties at maturity estimated at 4 km resolution across all land types and use classifications. Red stars represent Regional Feedstock 

Partnership locations and historical field trials used to transform model predictions to absolute 

yield estimates. The map grid was generated using Oregon State University’s PRISM-EM. 

(Source: Oregon State University, PRISM Climate Group)
DOT R&D Highlights

18 ORNL Sustainable Transportation Program

Evaluation of Heavy and Overweight Commercial Vehicles Department of Transportation R&D 

Contact: Adam Siekmann, siekmanna@ornl.gov, 865-946-1528

Research conducted by ORNL for federal highway safety agencies provides evidence of the 

danger presented by overweight commercial vehicles on the highways. It also found about a 

third of heavy vehicles inspected to have dangerous defects.

Trucks account for approximately 64% of the total freight weight moved in the United States 

each year. Currently, most combination commercial vehicles (tractor-trailer trucks) are allowed a maximum of 80,000 lb gross weight when traveling on the interstate. Exceeding the 

allowable gross weight not only damages infrastructure but also is potentially dangerous 

when heavy vehicles make emergency stops with faulty equipment.

ORNL is in the final year of a 3 year study funded by the Federal Highway Administration 

and Federal Motor Carrier Safety Administration (FMCSA) to evaluate the safety of heavy 

and overweight interstate commercial motor vehicles. Data were retrieved from roadside 

vehicle inspections performed on a voluntary basis by individual states specifically for this 

study. Currently, 30 of the 50 states have participated in the data collection with a total of 

7,842 vehicle inspections. The ORNL researchers developed software to analyze the raw 

data using mapping capabilities and custom filters to better understand trends in the 

results.

Many heavy vehicles are weighed using static and in-motion scales installed along the interstates. However, many of these vehicles are not physically inspected because the resources 

are not available to inspect every one.

The study provides evidence that commercial vehicles operating on the highway system are 

potentially more dangerous when they exceed recommended weight limits. Analysis also 

showed that 35% of the heavy vehicles inspected as part of this study were found to have 

vehicle defects that FMCSA considers sufficient to deem the vehicles unsafe to operate, or

take them out-of-service. This is higher than the national out-of-service rate for all commercial vehicles (25%).

The brake system of the vehicle was determined to be the main problem in nearly 60% of the 

heavy vehicles placed out of service. Tires are the second highest at 10%. The results of the 

analysis suggest a need for more resources directed toward the inspection of heavy vehicles 

and stricter maintenance procedures to detect problems on potentially dangerous vehicles

before they are operated. Also, there is a need to develop new tire and brake materials that 

support heavier loads to allow more freight to safely be moved along US highways.
2013 Annual Report DOT R&D Highlights

ORNL Sustainable Transportation Program 19

View of summary results from Washington state using the 

software developed. Washington had 317 inspections with 

a 52.4% out-of-service rate.

Publication

1. A. Siekmann and G. J. Capps, Heavy and Overweight Vehicle Defects Interim Report,

ORNL/TM-2012/575, Oak Ridge National Laboratory, 2012.

Intelligent Transportation Systems Asset Viewer

Contact: Steve Gordon, gordonsr@ornl.gov, 865-946-1313

At the annual Intelligent Transportation Society of America meeting held in April 2013, the 

US Department of Transportation (DOT) unveiled the Intelligent Transportation Systems 

(ITS) Asset Viewer, an online application that uses visual mapping technology to identify 

the locations of specific ITS technologies. These technologies include assets like message 

boards, cameras, traffic sensors, and road weather information systems. This system was 

developed by ORNL staff as part of the ITS Deployment Tracking Project in which ORNL 

tracks and analyzes progress in deployment of ITS technology for DOT.

Mike Schultze and Steve Gordon of ORNL developed the viewer, and they helped provide 

demonstrations during the meeting.

This is an important new resource for DOT to use in analyzing the impact of investments in 

technology within cities as well as rural areas nationally. Where previously only the number 

of assets within major cities was available, now the spatial array of deployment can be seen 

on the road network, showing which road segments are covered by technology as well as 

the existence of gaps in coverage. Asset Viewer data will be integrated with other spatial 

data to permit analysis of the use of technology along road segments such as evacuation 

routes, high-traffic areas, areas with a high incidence of crashes, designated snow routes, 

and corridors supporting commercial trucking. The web site is already equipped with a 
DOT R&D Highlights 2013 Annual Report

20 ORNL Sustainable Transportation Program

number of utilities to support analysis, and future development will expand these features 

with a focus on making the site a key DOT analysis tool.

ITS assets in Little Rock.

The launch of ITS Asset Viewer was noted in the Research and Innovative Technology

newsletter and in the Secretary of Transportation blog:

One new tool that transportation fans might find interesting is RITA’s

[Research and Innovative Technology Administration] ITS Asset Viewer, 

launched just this week for the ITS-A meeting. This online, web-only app 

shows the wide range of intelligent transportation resources already in use 

from coast to coast—tens of thousands of highway messaging signs, traffic 

control devices, and more. And all of these items—overlaid in the app atop a 

map of the nation—are working to keep Americans and our economy 

moving as fast and as safely as we can. It is an impressive collection of items 

that demonstrates just how thoroughly ITS innovation is embedded into our 

national transportation system. 

DOT is funding a significant effort to further develop the site for 2014.

ORNL Helps Federal Motor Carrier Safety Administration Assess Funding

Contact: Stacy Davis, davissc@ornl.gov, 865-946-1256

ORNL is providing technical assistance to the Federal Motor Carrier Safety Administration to 

evaluate its Motor Carrier Safety Assistance Program (MCSAP) basic and incentive funding 

formulae, which determine the amount of funding each state receives under the program. The 

goal is to determine whether these formulae are still effective at providing financial assistance 

to states in a manner that maximizes commercial motor vehicle safety. ORNL will provide 
2013 Annual Report DOT R&D Highlights

ORNL Sustainable Transportation Program 21

recommendations on changes that will allow MCSAP to better support the financial needs of 

states and to assess what impact revised formulae would have on states.

MCSAP, a federal grant program, provides financial assistance to states to reduce the 

number and severity of crashes involving commercial motor vehicles. Investing grant 

monies in appropriate safety programs will increase the likelihood that safety defects, driver 

deficiencies, and unsafe motor carrier practices will be detected and corrected before they 

become contributing factors to accidents.

MSCAP also contributes to more uniform enforcement programs among states. It sets forth 

conditions for grant participation by state and local jurisdictions and requires that they 

adopt rules and standards compatible with the federal Motor Carrier Safety Regulations and 

Federal Hazardous Material Regulations for both interstate and intrastate motor carriers 

and drivers. The core national program elements are (1) driver/vehicle inspections,

(2) traffic enforcement, (3) compliance reviews, (4) public education and awareness, and 

(5) data collection.

ORNL uses an evidential reasoning approach in its evaluation. There is no single piece of 

information that enables reviewers to determine whether the MCSAP grant formula still 

allocates an appropriate amount of funds to states. However, much like in a court of law, 

numerous pieces of evidence can be assembled to support a determination. One piece of 

evidence is the correlation between crashes experienced by each state in FY 2011 and the 

number of road miles in that state. Another is the correlation between crashes in each state 

and the other three formula variables: estimated population, total vehicle miles traveled, 

and consumption of special fuels. Other statistics also are useful, such as percentage changes

in the number of crashes over time and number of fatalities over time. 

The study will conclude in the spring of 2014.

ORNL is helping MCSAP analyze the effectiveness of the funding it provides 

to states to reduce commercial motor vehicle crashes.
DOT R&D Highlights 2013 Annual Report

22 ORNL Sustainable Transportation Program

ORNL Analysts Work to Strengthen Motorcoach Safety

Contact: Stacy Davis, davissc@ornl.gov, 865-946-1256

From 2004 to 2012 more than 31,000 bus crashes occurred in the United States. As a result, 

the Federal Motor Carrier Safety Administration (FMCSA) has increased its oversight and 

enforcement activities related to motorcoach transportation. It has turned to ORNL for help 

in reviewing its statutory authority, regulations, policies, processes, and tools for 

motorcoach safety.

ORNL’s evaluation effort includes four interrelated tasks:

1. Conduct a quantitative data analysis of the motorcoach industry to provide quantitative 

views of its state

2. Conduct a legislative and regulatory review of motorcoach authorities and regulations 

to determine if new authorities and regulations are needed and if some existing ones are 

unused or underused

3. Review FMCSA motorcoach safety policies and processes to provide information on key 

safety issues and identify changes that could enhance motorcoach safety 

4. Conduct a gap analysis of the results of these reviews to identify legislative, regulatory, 

policy, and process weaknesses (i.e., gaps) and make recommendations for resolving 

them

ORNL provided FMCSA with recommendations for improving 

the safety of travel on motorcoaches like this one.

The effort’s primary product is a list of 61 gaps and suggested recommendations for their 

resolution. Several observations and conclusions were made in the course of developing the 

list.
2013 Annual Report DOT R&D Highlights

ORNL Sustainable Transportation Program 23

• FMCSA’s statutory authorities regarding motorcoach safety are sufficiently broad and 

flexible that they can be interpreted in ways that can meet almost any safety issues 

FMCSA needs to address.

• New authorities are needed in certain motorcoach safety areas.

• Most identified gaps involved issues relating to FMCSA motorcoach safety policies and 

processes rather than statutory authority and regulation. Increased effort should be directed toward five gap areas cited most often in the policy and process review: information technology tool interoperability, hours of service and driver fatigue, en-route 

inspections, ticket brokers and leasing agents, and public outreach on motorcoach safety awareness.

• Other important issues identified include

o uniformity of enforcement

o retention of the most effective aspects of the Quick Strike program (mentors, 

working in teams, vehicle inspections, and the conduct of more thorough 

investigations)

o evolution of FMSCA to a more science-based approach and risk-based inspection 

program to push the safety bar higher
Fuel Cell Technologies R&D Highlights

24 ORNL Sustainable Transportation Program

AFuel Cell Technologies R&D Highlights dvanced Microscopy Reveals Details of Proton Exchange Membranes

Contact: Karren More, morekl1@ornl.gov, 865-574-7788

Cost and durability are the major technical challenges facing proton exchange membrane

fuel cells (PEMFCs) for automotive applications. ORNL is developing novel methods to examine the material components within PEMFC membrane-electrode assemblies (MEAs) to 

uncover the underlying causes of their performance losses and thereby improve durability 

through careful materials modification and/or selection.

The platinum (Pt) cathode catalyst, in particular, significantly affects cost, since it is responsible for the highest fraction of the fuel cell material cost. State-of-the-art cathode catalysts 

consist of Pt or Pt-alloy nanoparticles dispersed on a carbon support material. A higherperformance catalyst could reduce the total amount of Pt required for the electrodes; however, catalysts that demonstrate high performance at beginning of life are many times less 

durable during use. It is imperative to develop a fundamental understanding of individual

MEA materials degradation mechanisms to enhance performance and durability through 

materials optimization. ORNL has established analytical methodologies for characterizing 

PEMFC MEAs using state-of-the-art high-resolution transmission electron microscopy

(TEM), scanning transmission electron microscopy (STEM), and spectroscopy. 

Recently, ORNL contributed to understanding the mechanism(s) of carbon corrosion, a significant contributor to performance loss of the cathode. ORNL demonstrated how carbon 

support microstructures are correlated with initial catalyst dispersions—mechanisms by 

which carbon oxidizes and corrodes—and how carbon corrosion affects catalyst performance and stability. Cathode degradation at high potential holds is due to carbon corrosion 

and the concomitant loss of Pt as a result of Pt encapsulation in the densified/oxidized

cathode layer, as well as Pt dissolution and subsequent migration into the membrane.

The degree of carbon corrosion relies specifically on the graphitization level of the carbon 

support. High-surface-area carbon (HSAC) is highly disordered with a defective mesographitic outer shell and an amorphous core that make it highly susceptible to oxidation. On 

the other hand, low-surface-area carbon (LSAC) comprises a highly ordered/faceted graphitic shell with a hollow core. LSAC exhibits significantly greater stability at high potentials and resists carbon corrosion as a result of the higher graphitization of the surface.

Electrochemical surface area loss of Pt is controlled by Pt coalescence, which depends on the 

initial Pt particle dispersion and is a direct result of the carbon support material used. A 

higher Pt dispersion is achieved on HSAC than on LSAC, where the catalyst particle dispersion is essentially controlled by the surface defect density of the carbon support. Thus the 

most critical structural factor affecting cathode durability is ultimately the defect density 

present on the carbon surface, which is controlled by the extent of graphitization of the support and dictates the nanoparticle dispersion. The graphitization and defect structure of the 

carbon support show better correlation with corrosion rate than the Brunauer–Emmett–

Teller surface area of the carbon. 
2013 Annual Report Fuel Cell Technologies R&D Highlights

ORNL Sustainable Transportation Program 25

In addition to this work, through multiple collaborations with industry and academia, 

ORNL has continued to serve the analytical needs of fuel cell researchers by developing 

novel microscopy techniques and analytical methodologies.

TEM images of cathode catalyst materials, Pt particles dispersed on HSAC (a) and LSAC (b).

Melt-spun PAN Fibers for Gas Storage Tanks Meet Program Milestone 

Contact: Robert Norris, norrisrejr@ornl.gov, 865-576-1179

ORNL achieved a major milestone during FY 2013 by producing carbon fiber from meltspun polyacryolnitrile (PAN) with properties that meet go/no-go decision points for the 

hydrogen program. The achievement demonstrates the initial feasibility of this approach.

The exceptional strength-to-weight ratio of carbon fiber composites makes them prime candidates for both mobile and stationary storage tanks for use with materials-based, cryogenic, or high-pressure gas. Cost is the primary issue for composite tanks, and carbon fiber cost 

and manufacturing cost are the key challenges. Current projections of the manufactured cost 

per unit for production volumes are about a factor of nine above storage system targets. The 

base cost of the carbon fiber accounts for an estimated 40–70% of the unit cost; the precursor 

accounts for ~40% of that and thermal processing of the precursor the rest. Melt spinning of 

precursor fiber could be much less expensive than the solution spinning process exclusively 

used today.

This project consists of tasks focused on precursor development led by Virginia Tech and 

conversion process improvements led by ORNL. Melt-spinnable PAN is the primary precursor option. If successful, melt spinning is expected to be significantly less costly than wet 

spinning and to produce high-quality, relatively defect-free precursor. Reaching that goal 

requires concurrent activities to develop melt-stable PAN copolymers and blends and the 

processes necessary to successfully spin them into filamentary tows.

For this demonstration, some baseline high-molecular-weight PAN-based formulations are 

being used that, while representative of processing requirements ultimately required to 
Fuel Cell Technologies R&D Highlights 2013 Annual Report

26 ORNL Sustainable Transportation Program

meet program goals, probably cannot themselves be converted into carbon fiber meeting 

those goals. Development of an adequate precursor formulation is a major goal for the next 

phase. Significant engineering obstacles have been overcome using the simple experimental 

equipment available in the project to demonstrate this approach is feasible, including improved spinneret design and construction, improved filtration, means of maximizing the 

use of small samples by integrating purging materials to maintain open holes as the sample 

is expended, enhanced extrusion barrel heating, a larger spinning pressure chamber, and 

indexed take-up winding patterns. Most recently, a capability for precursor fiber drawing in 

a separate process between spinning and conversion has been incorporated.

The drawn PAN/vinylacetate fibers were successfully converted to carbon fibers. The carbonized fibers have a tensile strength of over 150 ksi and a modulus higher than 15 msi, 

meeting the goal of the critical go/no-go milestone for feasibility demonstration. Other 

samples significantly exceeded this critical milestone target, including one with over 250 ksi 

and 25 msi. The next phase will demonstrate larger quantities of carbon fiber with improved 

properties through continued development of precursor formulations, spinning techniques, 

and carbon fiber conversion recipes.

New continuous fiber drawing system with steam bath.

Publications and Presentations

1. F. L. Paulauskas and R. E. Norris, “Melt processable PAN precursor for high strength, 

low-cost carbon fibers,” Fuel Cell Technologies FY 2013 Annual Progress Report, US Department of Energy, 2013.

2. F. L. Paulauskas, “High strength carbon fibers and status report,” presented at Hydrogen Storage Tech Team Meeting, April 18, 2013.

3. F. L. Paulauskas, “High strength carbon fibers,” presented at 2013 DOE Hydrogen Program and Vehicle Technologies Annual Merit Review and Peer Evaluation Meeting, 

May 13–17, 2013. 
2013 Annual Report Fuel Cell Technologies R&D Highlights

ORNL Sustainable Transportation Program 27

Market Prospects of Fuel Cell Plug-in Hybrid Electric Vehicles

Contact: Zhenhong Lin, linz@ornl.gov

A study conducted at ORNL found that fuel cell plug-in hybrid electric vehicles (FC PHEVs) 

could be competitive both in the near term and in the long run for several reasons. In the 

near term, when few hydrogen refueling stations are available, the plug-in battery will reduce refueling inconvenience for FC PHEV users. In the long run, both FCs and plug-in batteries will become cheaper and the FC PHEV could become a competitive powertrain.

The study, published in the International Journal of Hydrogen Energy, used the ORNL MA3T 

model to predict future sales of 40 vehicle powertrain choices among 1,458 consumer segments. Vehicle data are based on output from Argonne National Laboratory’s Autonomie 

model. 

The chart shows market shares predicted through 2050 for conventional gasoline and diesel 

vehicles (ConvICE), hybrid electric vehicles (HEV), gasoline plug-in hybrid electric vehicles 

(PHEV), battery electric vehicles (BEV), hydrogen engine vehicles (H2 ICE), fuel cell vehicles 

(FCV), and FC PHEVs. The four scenarios include Base, the baseline scenario; ProgramGoal, 

in which all DOE technical targets are met on time; Base+FC, only FC and hydrogen-related 

targets met on time; and Base+P40Bat, only battery and motor targets met on time. Market Shares of Light-duty Vehicles

Base+FC

Base+P40Bat ProgramGoal

Base

Market shares of four scenarios by technology category.

Both FCs and plug-in batteries could dominate the light-duty vehicle market. That is, either 

could capture more than a 50% market share (as a result of the FC PHEV, which includes 

both components). If all DOE technical targets are met on time (ProgramGoal case), FCs 

could capture about 64% of the market and plug-in batteries about 72%.
Fuel Cell Technologies R&D Highlights 2013 Annual Report

28 ORNL Sustainable Transportation Program

The remarkable synergy between the FC and the plug-in battery is mainly due to their shared 

powertrain option—the FC PHEV—which appears to be competitive across all scenarios in 

both the short and long term, for some reasons common across both periods and some that 

differ. Low energy cost is a common reason. The FC PHEV has lower energy costs than a 

spark ignition (SI) PHEV (a PHEV with a gasoline engine) because it uses hydrogen fuel, 

which is cheaper (partly because of subsidies) and more efficient than gasoline. The FC PHEV 

also achieves lower energy costs than an FCV by fueling some miles with slightly cheaper 

electricity from the utility grid. Compared with BEVs, FC PHEVs have a longer driving range. 

Compared with FCVs, FC PHEVs consume less hydrogen fuel and thus require less frequent 

refueling, an important advantage in the early market with low hydrogen availability.

Over time, this range advantage of FC PHEVs will diminish as the hydrogen infrastructure 

expands, but then a long-term advantage emerges—a competitive price for the FC PHEV 

due to technological progress in both FCs and plug-in batteries. By 2045, an FC PHEV with a 

10 mile all-electric range is predicted to be slightly less expensive than an SI PHEV with a 

10 mile all-electric range if all technical targets are met on time. The competition among SI 

PHEVs, FCVs, and FC PHEVs reflects tradeoffs among vehicle price, energy cost, and refueling inconvenience.

Publication

1. Z. Lin, J. Dong, and D. L. Greene, “Hydrogen vehicles: Impacts of DOE technical targets 

on market acceptance and societal benefits,” International Journal of Hydrogen Energy, 

38(19), 7973–7985 (2013).

2. D. L. Greene, Z. Lin, and J. Dong, “Analyzing the sensitivity of hydrogen vehicle sales to 

consumers’ preferences,” International Journal of Hydrogen Energy, 38(36), 15857–15867

(2013).
Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 29

Vehicle Technologies R&D Highlights Analysis

My Plug-in Hybrid Calculator @www.fueleconomy.gov

Contact: Zhenhong Lin, linz@ornl.gov

ORNL has implemented an online calculator, My Plug-in Hybrid Calculator, on the website

www.fueleconomy.gov. The website, operated by ORNL for DOE, provides official Environmental Protection Agency fuel economy data for more than 1000 vehicle models.

Using this flexible and user-friendly tool, consumers need only answer a few questions to 

obtain personalized estimates of energy costs and gas station visits for operating a specific 

plug-in hybrid electric vehicle (PHEV).

The user picks from a list of PHEV products on the market, and the system automatically 

reads the efficiency data for a chosen product. The user then picks the Simple Driving form 

that asks two questions about driving patterns: typical daily distance and annual driving 

distance. After the user answers a few questions about the availability of home and workplace charging and specifies gasoline and electricity prices, the calculator provides personalized estimates of energy costs, energy consumption, and number of gas station visits.

The user chooses a PHEV product.
Vehicle Technologies R&D Highlights 2013 Annual Report

30 ORNL Sustainable Transportation Program

Answers two questions about personal driving habits.

Answers brief questions on charging availability.
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 31

And receives personalized estimates for PHEV operation.

Publications

1. Z. Lin, J. Dong, C. Liu, and D. Greene, “Estimation of energy use by plug-in hybrid electric vehicles: Validating gamma distribution for representing random daily driving distance,” Transportation Research Record 2287(1), 37–43 (2012). 

2. Z. Lin, “Optimizing and diversifying the electric range of plug-in hybrid electric vehicles 

for U.S. drivers,” International Journal of Alternative Powertrains 1(1), 108–194 (2012). 

Impact of On-Road Wireless Charging on the Electric Vehicle Market

Contact: Zhenhong Lin, linz@ornl.gov, 865-946-1308

Ongoing studies at ORNL find that dynamic wireless power transfer (DWPT), or on-road 

charging, could significantly increase the market adoption of plug-in electric vehicles 

(PEVs). The sales impact is predicted to be much greater for battery electric vehicles than for 

plug-in hybrid electric vehicles.

Among consumer segments, the predicted impact varies significantly. Overall, there would 

be larger effects on consumers who lack adequate charging capability at their homes or 

workplaces and on consumers with high driving intensity. DWPT could also abruptly expand the PEV consumer base once the availability of on-road charging becomes sufficient 
Vehicle Technologies R&D Highlights 2013 Annual Report

32 ORNL Sustainable Transportation Program

(~0.8% of all roads) and it becomes a viable alternative to home or workplace charging for 

consumers who do not have access to either.

The research estimates cumulative PEV sales between 2020 and 2050 given different levels 

of DWPT deployment and improvements in battery technology. It also analyzes the likely 

effect on sales of two different traffic patterns—highly concentrated traffic volume (San 

Francisco metropolitan area) or more diffuse traffic (San Diego metropolitan area)—to reveal estimation uncertainty and indicate needs for further spatial analysis.

Estimated cumulative PEV sales during 2020–2050. (DWPT deployment starts in 2020 to 0.5% of 

all roads [WPT0.5%] or 1.0% [DWPT1%] roads by 2050. The impact varies among scenarios and 

depends on whether battery technology is accelerated by 10 years [+Bat10] and whether 

the traffic concentration follows the San Diego pattern [+SD], the San Francisco [+SF] pattern, or the average [+AVG]). Comparing the Base or Base+Bat10 scenarios, the impact is 

greater on BEV sales than on PHEV sales.
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 33

Impact of DWPT by consumer segment. DWPT at 0.8% of roads could significantly increase 

purchase probabilities across consumer segments, even those who otherwise probably 

would not consider battery electric vehicles, such as those without home or workplace 

charging and those who drive frequently.

Publication

1. Z. Lin and J. Li, “Dynamic wireless charging: Potential impact on plug-in electric vehicle 

adoption,” accepted for publication by Society of Automotive Engineers 2014 World 

Congress.
Vehicle Technologies R&D Highlights 2013 Annual Report

34 ORNL Sustainable Transportation Program

Costs of Oil Dependence to the US Economy 

Contact: Changzheng Liu, liuc2@ornl.gov, 865-946-1306

ORNL continued to develop its Oil Security Metrics Model (OSMM) in 2013 and used it to 

estimate the costs of US oil dependence from 1970 to 2012 and their economic and other effects. Since the 1970s, oil dependence has been an important national security and economic 

problem for the United States. To a great extent, national security issues associated with oil 

dependence are a consequence of its potential damage to the US economy. To inform decisions about national energy policy, it is important to measure those costs.

Oil dependence is not simply a matter of how much oil is imported but is a syndrome, a 

combination of factors that together create economic, political, and military problems. It 

consists of the concentration of the world’s oil supply in a small group of states with monopoly power, together with the demand-side vulnerability of the US economy to higher oil 

prices and price shocks. US vulnerability depends on how much oil it consumes, the lack of 

ready substitutes for oil, and how much oil it imports. 

OSMM is built upon linear supply and demand equations. It measures three types of dependence costs: wealth transfer from oil consumers to producers due to monopolistic pricing, loss of potential gross domestic product (GDP) output due to higher than competitive 

market prices, and costs of adjusting to sudden, large price changes (macroeconomic adjustment costs).

Past estimates showed oil dependence costs peaking at about $350 billion in 1980 and 1981. 

The ORNL study indicates oil dependence costs reached that level in 2007, soared to approximately $550 billion in 2008, fell back to just over $300 billion in 2009 and 2010, and increased again to $500 billion in 2011–2012. However, US GDP today is more than twice its 

1980 GDP. Relative to GDP, oil dependence costs were 3.5% in 2008 and 4.5% in 1980. The 

cumulative, direct costs of oil dependence to the US economy from 2005 to 2012 are estimated at approximately $3.3 trillion. 

Monte Carlo simulations reflecting uncertainties in key parameters produced ranges including 90% of the simulation estimates of $429 billion to $602 billion, with a mean value of $508 

billion, for oil dependence costs in 2008 and from $268 billion to $339 billion, with a mean of 

$302 billion, for 2010. The 5th to 95th percentile range for total costs from 2005 to 2012 is $2.9 

trillion to $3.7 trillion.

How much of the cost of oil dependence can be avoided? History suggests reduced demand 

and increased non-OPEC supply, as was seen between 1990 and 2002, could reduce oil dependence costs by an order of magnitude. A comprehensive strategy of efficiency improvement, substitution of other energy sources for petroleum, and increased domestic energy 

production could do the same in the future.

Publications and Presentations

1. D. L. Greene, R. S. Lee and J. L. Hopson, “OPEC and the costs to the U.S. economy of oil 

dependence: 1970–2010,” White Paper 1-13, Howard H. Baker, Jr., Center for Public 

Policy, University of Tennessee (2013).
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 35

2. D. L. Greene, “The future of the world oil market,” presented at the annual meeting of 

the International Subcommittee of the Energy Committee of the Transportation Research 

Board, Washington, D.C., January 15, 2013.

3. D. L. Greene, “The economics of US oil dependence and implications for public policy,” 

lecture at The Kennedy School, Harvard University, October 22, 2012.

4. D. L. Greene, “The challenge of energy sustainability in surface transportation,” presented at the University Transportation Center Spotlight Conference on Sustainable Transportation, Keck Center, National Academies, Washington, D.C., November 8, 2012.

$0 

$100 

$200 

$300 

$400 

$500 

$600 

1970 1975 1980 1985 1990 1995 2000 2005 2010

Billions of 2012 $

Costs of Oil Dependence to the U.S. Economy: 1970-2012

Wealth Transfer

Dislocation Losses

Loss of Potential GDP

Annual cost of oil dependence to US economy (1970–2012).

Cumulative oil dependence costs from 2005 to 2012.
Vehicle Technologies R&D Highlights 2013 Annual Report

36 ORNL Sustainable Transportation Program

Learning-from-History Feature of the MA3T Model

Contact: Zhenhong Lin, linz@ornl.gov

Market Acceptance of Advanced Automotive Technologies (MA3T), a consumer choice 

model developed by ORNL, endogenously projects sales of competing vehicle technologies 

among consumer segments. MA3T is a flexible, credible tool for analyzing how technology, 

behavior, infrastructure, and policy affect sales of new technologies and the resulting societal, environmental, and economic impacts.

During FY 2013, ORNL developers implemented a Learning-from-History (LFH) feature to 

enhance the prediction accuracy of MA3T. The LFH feature includes two functions—

Automatic Calibration and Independent Validation. With Automatic Calibration, MA3T is 

calibrated with historical sales and prices of vehicle products during 2005–2011. The calibrated MA3T is then independently validated by prices and sales of cars, light-duty trucks, 

plug-in hybrid electric vehicles, and battery electric vehicles during 2012. With 2013 sales 

and price data becoming available, LFH calibration and validation will be further improved.

MA3T analyzes how aspects of technology, infrastructure, consumer behavior, and public 

policies affect sales of vehicle technologies and the social and economic impacts that result 

from those sales trends.

MA3T forecasts sales of 40 vehicle choices (conventional, natural gas, diesel, plug-in, battery 

electric, and hydrogen vehicles for both passenger cars and light-duty trucks) among 1,458 

consumer segments in response to changes in technologies, infrastructure, consumer preferences, energy prices, and policies. 

The consumer segments included represent demand versatility with respect to regions, residential areas, driving patterns, technological attitudes, access to home charging, and access 

to charging at work. The consumer segmentation, together with the wide range of represented technologies, allows analysis of who buys what technologies, by how many, and 

when. With comprehensive linkages to market driving forces, MA3T is capable of identifying research and development priorities, infrastructure roll-out strategies, and smart policies for the purpose of promoting a specific vehicle technology, including fuel cell electric 
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 37

vehicles. It can also be used to evaluate and justify any of the previously proposed strategies. MA3T is calibrated and independently validated with historical sales and price data. It 

can be executed on any personal computer with MS Excel 2010 or later versions.

Publications and Presentations

1. Z. Lin, D. Greene, and C. Liu, Documentation for the MA3T Model, working document.

2. Z. Lin, “Modeling market acceptance of plug-in electric vehicles,” presented at the Joint 

Seminar of Vehicle Electrification Group and Climate and Energy Decision Making Center, Carnegie Mellon University, April 9, 2013.

3. Z. Lin, “Updating and enhancing the MA3T vehicle choice model,” presented at 2013 

DOE Vehicle Technologies Program Annual Merit Review, Washington, D.C., May 13,

2013.

Optimal Market Mix of BEV Ranges for US Consumers

Contact: Zhenhong Lin, linz@ornl.gov

A study by ORNL researchers estimates the optimal market mix of battery electric vehicle 

(BEV) driving ranges for US consumers. The estimated mix serves as a basis for evaluating 

the market prospects of BEVs and their impact on petroleum consumption and greenhouse 

gas emissions.

Properly determining the driving range is critical for accurately predicting the sales and social benefits of BEVs. This study proposes a framework for optimizing the driving range by 

minimizing the sum of battery price, electricity cost, and range limitation cost—referred to 

as the “range-related cost”—as a measurement of range anxiety. The objective function is 

linked to policy-relevant parameters, including battery cost and price markup, battery use, 

charging infrastructure availability, vehicle efficiency, electricity and gasoline prices, household vehicle ownership, daily driving patterns, discount rate, and perceived vehicle lifetime. 

Assuming $400/kWh for battery cost and a sample (N=36664) representing new car drivers 

in the United States, the study estimates optimal BEV ranges among US drivers at 85 miles 

on average, with a standard deviation of about 40 miles. This suggests a wide dispersion of 

optimal BEV range among US drivers owing to variations in driving patterns and household vehicle ownership. The average optimal range among US drivers is found to be largely 

inelastic. The top two influential factors are range maximum utilization, which increases 

with better charging infrastructure, and battery cost.
Vehicle Technologies R&D Highlights 2013 Annual Report

38 ORNL Sustainable Transportation Program

Sensitivity of average optimal range.

The quantitative results strongly suggest that ranges of less than 100 miles are likely to be 

more popular in the BEV market for a long period of time, during which battery costs are 

expected to decrease and charging infrastructure is expected to improve. These two forces 

affect optimal ranges in opposite directions: lower battery cost drives BEV demand toward 

longer ranges, whereas an improved charging infrastructure is found to drive demand toward shorter ranges. The bias of a single range assumption and the effects of range optimization and diversification in reducing such biases are both found to be significant.

(Left) Cumulative share of optimal range by battery cost. (Right) Cumulative share of optimal range by range maximum utilization.
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 39

Publications

1. Z. Lin, “Battery electric vehicles: Range optimization and diversification for U.S. drivers,” accepted by Transportation Science (2013).

2. Z. Lin, “Modeling market acceptance of plug-in electric vehicles,” presented at the Joint 

Seminar of Vehicle Electrification Group and Climate and Energy Decision Making Center, Carnegie Mellon University, April 9, 2013.
Vehicle Technologies R&D Highlights 2013 Annual Report

40 ORNL Sustainable Transportation Program

Combustion Engines and Fuels

Benefits of High-Octane Ethanol Blends

Contact: James Szybist, szybistjp@ornl.gov, 865-946-1248

Ethanol has a number of fuel properties that are advantageous in spark-ignited (SI) engines. 

Its high octane number and high latent heat of vaporization both contribute to superior antiknock properties. When engine hardware is configured to take advantage of these 

properties, ethanol can enable higher thermodynamic efficiency and higher power density 

than regular or premium grade gasoline.

A number of ORNL studies have illustrated that the superior anti-knock properties of a 

blend of ethanol and gasoline called E85 can result in higher thermodynamic efficiency even 

when the fuel blend contains as little as 51% ethanol and is blended with low-octanenumber hydrocarbon streams. In FY 2013, ORNL researchers conducted single-cylinder 

engine experiments illustrating that a 30% splash blend of ethanol with regular grade 

gasoline can improve fuel quality to such an extent that the power density of the engine is 

doubled in a high-compression-ratio configuration. The improved performance of the fuel 

reduces the fraction of the engine map in which the engine is knock-limited, thereby 

increasing its thermodynamic efficiency over a wide operational envelope. Perhaps more 

important, the increase in power density enables engine downsizing and downspeeding, 

which can result in system-level efficiency gains through reduced friction and higher load 

duty cycles for the same application.

Blends containing 15–30% ethanol improve anti-knock properties with a much smaller 

penalty in volumetric energy density than E85. Therefore, tank mileage from blends with as 

much as 30% ethanol in appropriately designed vehicles may be comparable to or better 

than the tank mileage of conventional gasoline vehicles.

Federal Corporate Average Fuel Economy (CAFE) regulations require higher-efficiency 

vehicles, and the federal Renewable Fuels Standard (RFS II) requires an increase in the use 

of bio-derived fuels. ORNL researchers are leading experimental efforts and outreach (via 

symposiums and conference panels) to automakers, energy companies, fuel distributors, 

and regulators to determine if it is logistically possible to take advantage of the higher 

engine efficiency offered by ethanol use to meet both CAFE and RFS II requirements. In 

addition, a DOE-funded project combining high-octane multi-cylinder engine experiments 

and drive cycle simulations is being conducted at ORNL in close coordination with 

industry.
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 41

Regular Grade Gasoline E30 Splash Blend

Efficiency contours over the operable speed/load range for regular grade 

gasoline and an E30 splash blend.

Publications and Presentations

1. J. Szybist and B. West, “The impact of low octane hydrocarbon blending streams on the 

knock limit of ‘E85,’” SAE International Journal of Fuels and Lubricants 6(1), 44–54 (2013). 

2. D. Splitter and J. Szybist, “An experimental investigation of spark ignited combustion 

with high octane bio-fuels and EGR, Part 1 of 2: Engine load range and downsize 

downspeed opportunity,” Energy & Fuels, in press.

3. D. Splitter and J. Szybist, “An experimental investigation of spark ignited combustion 

with high octane bio-fuels and EGR, Part 2 of 2: Fuel and EGR effects on knock limited 

load and speed,” Energy & Fuels, in press.

4. D. Splitter and J. Szybist, “Intermediate alcohol–gasoline blends, fuels for enabling 

increased engine efficiency and powertrain possibilities,” SAE Technical Paper 

14PFL-0262, to be presented at the 2014 SAE World Congress.

EGR Probe Applications Enable Engine Performance Advances

Contact: William Partridge, partridgewp@ornl.gov, 865-946-1234

ORNL has developed and applied an exhaust gas recirculation (EGR) probe in a cooperative 

research and development agreement (CRADA) project with Cummins, Inc. The probe’s 

development provides for crank-angle and spatially resolved CO2 measurements 

throughout an engine’s intake manifold. 

The probe has been used for a wide range of technologies related to developing advancedefficiency engine systems, including assessment, elucidation, and improvement of intake 

architectures; mixing physics; control strategies; cylinder-to-cylinder and cycle-to-cycle 

combustion uniformity; and numerical design tools such as computational fluid dynamics 

(CFD). 
Vehicle Technologies R&D Highlights 2013 Annual Report

42 ORNL Sustainable Transportation Program

The EGR instrument, based on mid-infrared laser absorption, uses a single-port probe and 

allows for simultaneous measurement from four separate probes. The physical probe is 

based on a 3/8 in. outside-diameter tube. Because the probe requires only a single access 

port to the measurement location, researchers have broad measurement possibilities on 

developed and advanced packaged engines, in which access often is limited. Minimal 

modification of the stock hardware is required. EGR distributions can be resolved via 

multiple access points and probe translation. The spectroscopic approach allows for 

simultaneous measurement of CO2 concentration and pressure to differentiate fluctuations 

associated with mixing and combustion versus density. Four-point multiplex measurements 

allow for rapid, extensive system mapping. The system is capable of resolving transients not 

only within individual valve events but also throughout the cycle.

In addition to assessing specific hardware, ORNL researchers can assess and improve the 

validity of the tools by comparing measured performance with that predicted by CFD 

design tools. This EGR probe application has enabled a 63% improvement in the baseline 

EGR mixing model. 

An EGR probe allows for on-engine measurements 

(photo). It has been used to improve the mixing model 

used for development and design by about 63% 

(bottom).

Presentation

1. W. Partridge, J. Yoo, R. Connatser, V. Prikhodko, R. Gonzalez, J. Parks, S. Geckler, 

A. Perfetto, A. Beck, M. Dane, R. Booth, and D. Koeberlein, “Cummins/ORNL FEERC 

0.5

1

1.5

2

2.5

3

3.5

0 50 100 150 200 250

CO2 (% Volume)

Time

Comparing Cummins' Mixing Model & EGR Probe Data 

Test Point 1 - Mixer A

Baseline EGR Mixing Model

Tuned EGR Mixing Model

EGR Probe Data

% P-to-P

59%

22%

20%
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 43

Combustion CRADA: Characterization and reduction of combustion variations,” 

presented at 2013 DOE Vehicle Technologies Program Annual Merit Review, Arlington, 

Va., May 16, 2013.

High-Efficiency Clean Combustion in Light-Duty Diesel Engines 

Contact: Scott J. Curran, curransj@ornl.gov, 865-946-1522

Advanced combustion has shown promise for achieving high thermal efficiencies with 

ultra-low NOx and particulate matter (PM) emissions. A reactivity controlled compression 

ignition (RCCI) engine uses in-cylinder blending of two fuels with different reactivities to 

improve control of the combustion process. At ORNL, drive cycle modeling of RCCI 

operation with diesel fuel and a 30% ethanol blend (E30) has demonstrated at least a 20% 

improvement in fuel economy over a 2009 port fuel injection (PFI) gasoline vehicle baseline. 

To model fuel economy and emissions over a variety of drive cycles, ORNL researchers 

developed and used an experimental RCCI engine map in vehicle system simulations. A 

4-cylinder General Motors 1.9 L diesel engine installed at ORNL was modified to include a 

port fuel injection system using conventional gasoline injectors and pistons that were 

designed for RCCI operation. 

ORNL multi-cylinder RCCI engine.

Experimental steady-state operating points on the modified engine were used to develop a 

speed/load map consistent with a light-duty drive-cycle and with enough detail for vehicle 

simulations. The engine map was developed using E30 fuel and certification-grade diesel 
Vehicle Technologies R&D Highlights 2013 Annual Report

44 ORNL Sustainable Transportation Program

fuel. The potential fuel economy of RCCI operation was evaluated using vehicle system 

simulations with experimental steady-state engine maps. Simulations used a multi-mode 

RCCI/diesel operating strategy by which the engine would operate in RCCI mode 

whenever possible but, at the highest and lowest engine operating points, would switch to 

diesel mode.

Multi-mode RCCI/conventional diesel combustion (CDC) operation was shown through 

vehicle system simulations to have the potential to offer a fuel economy improvement of 

over 20% compared with a 2009 gasoline PFI baseline. The peak efficiency from the RCCI 

operating map was within federal light-duty drive cycle speed and load range, whereas

CDC peak efficiency was well outside the federal range. However, the current range of the 

experimental RCCI engine map does not allow full coverage of many light-duty drive 

cycles. RCCI fuel economy improvements were observed despite lack of complete drive 

cycle coverage. 

Research results showed that NOx emissions are dependent on the drive cycle coverage of 

RCCI. Fuel use over the drive cycles showed that nearly equal amounts of gasoline and 

diesel fuel probably would need to be carried on board for RCCI multi-mode operation. 

During RCCI-only operation, fuel use was between 57.6% and 66.7% gasoline. 

Publications

1. S. Curran, R. Hanson, R. Wagner, and R. Reitz, “Efficiency and emissions mapping of 

RCCI in a light-duty diesel engine,” SAE Technical Paper 2013-01-0289 (2013). 

2. S. Curran, R. Wagner, and R. Hanson, “Reactivity controlled compression ignition 

(RCCI) combustion on a multi-cylinder light-duty diesel engine,” International Journal of 

Engine Research 13(3), 216–225 (2012).

3. V. Prikhodko, S. Curran, J. Parks, and R. Wagner, “Effectiveness of diesel oxidation 

catalyst in reducing HC and CO emissions from reactivity controlled compression 

ignition,” SAE International Journal of Fuels and Lubricants 6(2), 329–335 (2013). 

4. R. Hanson, S. Curran, R. Wagner, and R. Reitz, “Effects of biofuel blends on RCCI 

combustion in a light-duty, multi-cylinder diesel engine,” SAE International Journal of

Engines 6(1), 488–503 (2013). 

Novel Bimetallic Catalysts Improve Low-Temperature Oxidation 

Contact: Jim Parks, parksjeii@ornl.gov, 865-946-1283

Improvements in the efficiency of advanced combustion engines are creating challenges for 

emission control systems because greater fuel efficiency is leading to lower exhaust 

temperatures. Oxidation of CO and other pollutants by catalysts becomes more difficult at 

lower temperatures, but a new type of catalyst developed at ORNL is enabling improved 

low-temperature performance. 

A bimetallic catalyst composed of gold and copper, discovered through research in ORNL’s 

Basic Energy Sciences program, has unique properties that vary with exhaust conditions. 
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 45

Under rich conditions, an intermetallic nanoparticle of gold and copper forms; but under 

lean conditions, a core-shell particle forms with gold on the inside core surrounded by a 

copper oxide shell. It is this latter core-shell nanoparticle that exhibits improved lowtemperature oxidation. 

In studies on a bench flow reactor, the gold–copper catalyst achieves >90% conversion of 

CO below 100oC, compared with the typical 190oC lower limit for platinum-based catalysts. 

In simulated exhaust gases, NO was found to inhibit CO oxidation more than the gold–

copper catalyst. Researchers physically mixed a platinum-based catalyst with the gold–

copper catalyst to develop a combined catalyst, which demonstrated synergistic 

performance benefits and overall improvement in low-temperature oxidation compared 

with the more common platinum-based catalyst. CO oxidation performance “light-off” was 

attained at a temperature 30oC lower than the limit for the platinum catalyst, and NO 

oxidation efficiency was doubled. 

Hydrocarbons currently inhibit catalyst performance, and ongoing research is aimed at 

addressing hydrocarbon-induced limitations. However, the combination of gold–copper 

and platinum catalysts shows benefits when hydrocarbon emissions are minimal. The 

improved catalytic performance will enable advanced combustion engines to meet 

challenging emission regulation levels.

Micrograph of a gold–copper core-shell 

catalyst nanoparticle (top) and data 

showing a lower CO oxidation temperature 

for a gold–copper and platinum mixed 

catalyst in the presence of CO and NO 

(bottom).
Vehicle Technologies R&D Highlights 2013 Annual Report

46 ORNL Sustainable Transportation Program

First Systematic Study of GDI PM Size, Shape, and Composition

Contact: John Storey, storeyjm@ornl.gov, 865-946-1232

As direct fueling replaces port fuel injection in gasoline engines to boost fuel economy, a rise 

in particulate matter (PM) emissions has become an environmental challenge. Managing the 

amount of gasoline direct injection (GDI) PM emissions involves in-cylinder combustion 

control and/or after treatment with gasoline particulate filters (GPFs). ORNL researchers 

are seeking a better understanding of the origins of GDI PM emissions to improve incylinder control and lessen GPF requirements, thus preserving fuel economy gains while 

decreasing PM emissions. 

Using conventional particle sizing, ORNL researchers studied the soot that results from GDI 

engines and determined that particles in GDI soot spanned a much wider size range than 

soot particles produced by diesel engines. Researchers collected a representative sample of 

GDI soot using a transmission electron microscopy (TEM) grid sampler designed to collect 

the full spectrum of particle sizes. TEM has been used for two decades to show and describe 

soot particles; however, ORNL developed a new analysis technique for use with TEM 

images and was able to quantitatively measure the particle sizes and shapes to arrive at a 

size distribution.

Soot comprises chain-like structures, called aggregates, of tiny, spherical particles. Modern 

diesel engines, for example, produce aggregates of uniform primary particles measuring 20–

25 nm. Diesel PM uniformity is caused by high injection pressures and uniform atomization. 

Remarkably, researchers found GDI soot to be mostly aggregates of nanoparticles with a 

broad size range. The next most abundant particles were single spheroids, and a small 

fraction were irregular volatile particles that are common in exhaust. Inchoate soot with a 

thick, low-volatility film made up the remaining 10–20% of the total concentration.

The broad size range of particles indicates that fuel and air are not mixing completely incylinder. Fuel impingement on surfaces leads to fuel-rich zones that produce large 

nanoparticles, as well as areas that have less fuel, resulting in the formation of small 

particles. Bulk PM analysis determined that soot precursor compounds are present, and film 

on inchoate soot indicates incomplete formation of the primary soot particle and fuel-rich 

conditions. As soot builds up on a GPF, packing and pore penetration of small nanoparticles 

reduces the filter’s porosity and increases backpressure, resulting in a decrease in fuel 

economy. For this reason, quantitative studies of particle size and shape can guide incylinder control of GDI PM to either enhance GPF performance or eliminate the need for 

GPFs.
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 47

Doublets/

Aggregates

Single

Spheroids

Volatile

Irregular

Inchoate

Soot

50 nm

Particle Diameter (nm)

1 10 100 1000

1e+4

1e+5

1e+6

1e+7

1e+8

Online EEPS measurement

dN

/dlogd

p

Characteristics of GDI soot based on transmission electron 

microscopy and conventional particle sizing methods. The gray 

portion of the bars represents aggregates of nanoparticles; red, 

single spheroids; yellow, irregular volatile particles; and green, 

inchoate soot.

New Method Assesses Engine Efficiency Opportunities

Contact: K. Dean Edwards, edwardskd@ornl.gov, 865-946-1213

Increasingly stringent fuel economy regulations are driving innovative approaches to 

improving the efficiency of internal combustion engines. Less than half of the energy 

released during combustion typically produces work with the piston, while the remainder is 

consumed by inefficient processes including friction, pumping, heat loss, and hot exhaust 

leaving the tailpipe. The relationships among these processes are so highly interdependent 

that reducing one area of energy loss often increases another. Achieving a significant 

increase in engine efficiency requires a thorough understanding of these interdependencies 

as well as multiple, concurrent approaches to reduce losses and concentrate the remaining

energy into pathways (such as the exhaust) where it may be recovered to provide additional 

work.

Researchers at ORNL have developed a new method to account for the interdependent 

nature of energy use in an engine and assess the potential benefits of various efficiency 

improvement strategies. The approach begins with a complete first and second law 

thermodynamic analysis of experimental and/or simulation data to evaluate how energy is 

consumed in the engine. The potential efficiency benefits of given strategies are then 
Vehicle Technologies R&D Highlights 2013 Annual Report

48 ORNL Sustainable Transportation Program

evaluated by applying thermodynamics-based, multiplicative factors to estimate reductions 

in energy consumption and predict how the recovered energy may be redistributed among 

the other energy pathways. The highly interdependent nature of the energy pathways in the 

engine obviously makes these predictions and the selection of appropriate factors very 

difficult. However, the mathematical simplicity of this approach allows for extensive 

sensitivity and uncertainty analyses to be conducted to provide a statistical range of 

potential benefits for a given efficiency-improvement strategy.

ORNL is working closely with industry stakeholders through the US Council for 

Automotive Research partnership to apply this new technique to benchmark data from 

state-of-the-art light-duty engine platforms. Researchers will use the data to develop ways 

to maximize efficiency for light-duty applications. Potential benefits have been calculated

for a light-duty diesel engine for a particular scenario in which reductions in friction, 

pumping losses, and heat loss provide increased work output with the piston; and energy is 

concentrated in the exhaust, where additional work can be produced with a waste heat 

recovery strategy (e.g., a bottoming cycle). This combination of strategies is predicted to

potentially provide a combined efficiency gain of approximately five percentage points.

Example scenario for a light-duty diesel engine at part load showing potential 

opportunity for efficiency gains from reducing or recovering lost energy by the 

percentages shown on the y-axis.

Impacts of Biodiesel Impurities on Emissions Control System

Contact: Todd Toops, toopstj@ornl.gov, 865-946-1207

One of the ways the United States can increase energy security is by expanding 

domestically-produced renewable fuels for transportation. However, each new fuel must be 

fully investigated for potential incompatibilities because even small changes in composition 

can have a significant impact on a vehicle’s emissions control system and durability. 

Biodiesel is an emerging, domestically-produced renewable fuel that has great potential but 

needs to be evaluated to alleviate concerns of the transportation industry.

In a project co-sponsored by Fuels Technologies and Propulsion Materials in conjunction 

with the National Biodiesel Board, researchers at ORNL and National Renewable Energy 
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 49

Laboratory (NREL) are studying impurities regulated in biodiesel, giving particular 

attention to the impacts of sodium, potassium, and calcium impurities.

Biodiesel relies on NaOH or KOH in its synthesis process, but these components must be 

removed. Current specifications require less than 5 ppm Na + K and 5 ppm Ca + Mg in 

100% biodiesel (B100) fuel. Diesel fuel is limited to 5% biodiesel, although some vehicles 

have been certified for up to 20% biodiesel (B20). To study the impact of these metals at a 

B20 level, NREL and ORNL initiated a collaborative accelerated aging study. Both the full 

useful life metal exposure and on-vehicle evaluation of the emissions control system were 

performed at NREL. The vehicle passed the nitrogen oxides (NOx) emissions standards at 

the end of the test. However, some elevated emissions points with sodium and potassium 

exposure highlighted the need for further analysis.

Flow bench reactor evaluations at ORNL and Ford Motor Company showed the fronts of 

the sodium- and potassium-exposed systems had a 10 to 20% decrease in NOx reduction 

activity on the selective catalytic reduction (SCR) catalyst. At ORNL, the materials 

characterization illustrated a surprising deactivation mechanism for the sodium and 

potassium SCR samples: those SCR samples had a thin layer of CuO on the surface of the 

washcoat. This layer showed that sodium and potassium were displacing copper from the 

zeolite, and the copper was migrating to the surface. This did not eliminate the overall 

reactivity of the SCR catalyst but decreased it significantly so that the system would fail 

emissions tests if the entire sample were in this state. The dark CuO covered only the front 

one-third of the front catalyst; the rear catalyst was unaffected.

This research addressed concerns of vehicle manufacturers regarding the introduction of 

biodiesel at levels up to 20%. The results demonstrated the importance of strict adherence to 

maintaining metal content standards within the required fuel specification.

Publication

1. J. B. Williams, R. McCormick, T. Toops, A. Wereszczak, E. Fox, M. Lance, G. Cavataio, 

D. Dobson, J. Warner, R. Brezny, D. Brookshear, and K. Nguyen, “Impact of fuel metal 

impurities on the durability of a light duty diesel aftertreatment system,” SAE Technical 

Paper Series 2013-01-0513 (2013).
Vehicle Technologies R&D Highlights 2013 Annual Report

50 ORNL Sustainable Transportation Program

0.2 gram/mile NOx EPA standard

 

 

only observed on Naand K-aged samples

B20 + Na

B20 + K

B20 + Ca

(Top left) Each of the complete systems met the emissions standard at the end of the full 

useful life durability evaluation; however, materials characterization showed that the 

sodium- and potassium-aged samples removed copper from the Cu-zeolite SCR 

catalyst. The micrographs at right show a thin layer of CuO on the washcoat surface.

B20+Ca

B20+Na

B20+K
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 51

Energy Storage

ORNL Produces Lithium-Ion Battery Electrode via Water-Based Process

Contact: Claus Daniel, danielc@ornl.gov, 865-241-9521

ORNL is working to substantially reduce the production cost of lithium-ion batteries (LIBs) 

while increasing sustainability in the battery manufacturing process. DOE has set a battery 

cost target for LIB-based electric vehicles (EVs) of $125/kWh by 2020; this target requires a 

threefold improvement over the current cost of ∼$500/kWh. 

To meet this ambitious goal, researchers are looking to conventional battery manufacturing 

to find methods to develop less expensive materials and processing methods, which presently make up more than 80% of the total cost of an EV battery. Conventional electrodes are 

manufactured by slurry processing with a binder of polyvinylidene fluoride (PVDF) and a 

solvent of N-methyl-2-pyrrolidone (NMP). NMP is toxic, flammable (it produces vapors 

during electrode manufacturing), and expensive (it requires costly solvent recovery). ORNL 

is developing an aqueous processing method for LIB manufacturing in which NMP (at a 

cost of $1–2/liter) is replaced with deionized water, which costs just $0.015/liter.

The use of deionized water significantly reduces raw materials and processing costs and 

eliminates the process for recovery and treatment of NMP. The process is also more environmentally benign, an advantage that will be critical in mass production of LIBs. This novel processing route is estimated to reduce the full battery pack cost by up to 20%.

The rate performance of LiNi0.5Mn0.3Co0.2O2 cathodes with various water-soluble binders 

from aqueous processing was compared with the rate performance of cathodes with a PVDF 

binder from NMP-based processing. The cathodes produced via aqueous processing 

demonstrated superior rate performance, an indication that switching from NMP-based to 

aqueous processing of LIB electrodes offers more than just dramatically reduced costs. 

Aqueous processing of the conventional graphite anode is a commonly used, relatively mature technology. However, adapting it to work with the diverse array of LIB cathodes has 

proved to be a challenge. ORNL is tackling the challenge by understanding the colloidal 

chemistry of each cathode component for effective dispersion, screening water-soluble binders for superior adhesion and electrode integrity, optimizing mixing protocols for uniform 

suspensions, improving the surface energy of the aluminum current collector for better wettability of cathode dispersions, developing drying procedures for effective moisture removal, 

and quantifying the effect of residual moisture on battery performance. During the course of 

this research, ORNL successfully manufactured DOE’s first fully water-processed LIB.

Publications and Patent

1. J. Li, B. Armstrong, J. Kiggans, C. Daniel, and D. Wood, “Optimal polyethyleneimine 

concentration and mixing sequence for LiFePO4 aqueous nanoparticle dispersions,”

Journal of Colloid Interface Science 405(1), 118–124 (2013).
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52 ORNL Sustainable Transportation Program

2. J. Li, B. L. Armstrong, J. Kiggans, C. Daniel, and D. L. Wood, III, “Lithium ion cell performance enhancement using aqueous LiFePO4 cathode dispersions and polyethyleneimine dispersant.” J. Electrochem. Soc. 160(2), A201–A206 (2013).

3. J. Li, B. L. Armstrong, C. Daniel, and D. L. Wood, III, “Aqueous Processing of Composite Lithium Ion Electrode Material,” US Patent application 13/651270, filed October 12, 

2012.

0

20

40

60

80

100

120

140

160

0.1 1 10

TRD202A

Latex

Nafion

SBR

PVDF

C-rate (C)

DIscharge Capacity (mAh/g)

Comparison of the rate performance of NMC 532 cathodes produced 

via aqueous processing and NMP-based processing with a PCDF binder. 

Performance of the cathodes from aqueous processing is superior. 

Computer-Aided Engineering for Batteries

Contact: Sreekanth Pannala, pannalas@ornl.gov, 865-574-3129

In the ongoing complex quest to develop better, longer-lasting batteries for electric and 

hybrid-electric vehicles, researchers at ORNL are turning to computer-aided engineering 

and a predictive simulation capability that can guide rapid design by considering 

performance and safety implications of different chemistry and materials choices. The 

Computer Aided Engineering for Batteries (CAEBAT) Open Architecture Software (OAS)

framework is designed for multiphysics and multiscale battery models. It also enables 

integration of different components representing physics for charge and thermal transport, 

electrochemistry, mechanical stresses, and degradation.

This project is the answer to the substantial need for design tools for batteries that can 

leverage the significant investments in modeling efforts made across DOE and academia. 

For the first time, researchers are creating an open, flexible computational framework that 

incorporates diverse existing capabilities as well as new capabilities developed by the 

vehicle technologies research community. Within this framework, scientists and designers 
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 53

can use decades of development, verification, and validation of modeling tools for 

individual physics domains and focus on new issues associated with coupling and multiphysics interaction.

The models operate and interact across the porous 3-dimensional structure of the electrodes 

(cathodes and anodes), the solid or liquid electrolyte system, and the other battery 

components. Underlying lower-length processes are accounted for through closure 

equations and submodels based on resolved quantities. Most important, the multi-material 

interfaces are kept intact. 

The computational framework has a modular structure so that components corresponding

to particular physical phenomena can be interchanged flexibly and consistently with similar 

components. Each simulation component in the OAS framework is equipped with coupling 

interfaces that are wrapped around standalone code. These interfaces convert native data 

from these components to the data format used by the OAS framework. This enables the 

components to remain unchanged and yet fully interact with the framework and other 

components. Extensibility of the framework allows easy integration of new models as they 

are developed. 

The CAEBAT OAS framework approach allows researchers to simulate electrochemical and 

thermal behavior on the cell, module, and pack levels as well as mechanical response of the 

battery to a crash or mechanical abuse conditions.

Publication

S. Allu, S. Kalnaus, W. Elwasif, S. Simunovic, J. A. Turner, and S. Pannala, “A new open 

computational framework for highly-resolved coupled three-dimensional multiphysics 

simulations of Li-ion cells,” Journal of Power Sources 246, 876–886 (2014).

Studying High-Voltage Battery Cathodes for Electric and Hybrid Vehicles

Contact: David Wood, wooddl@ornl.gov, 865-574-1157

Lithium-ion batteries are a leading energy storage technology for electric vehicles (EVs). 

Lithium- and manganese-rich nickel/manganese/cobalt (LMR-NMC) cathodes deliver 

higher voltage and energy density in lithium-ion batteries than other candidates, but they 
Vehicle Technologies R&D Highlights 2013 Annual Report

54 ORNL Sustainable Transportation Program

experience voltage fade and capacity losses over repeated cycles. To understand the 

mechanisms underlying these performance issues, researchers are using ORNL’s 

capabilities in materials characterization to explore the structure of LMR-NMC materials.

The project uses several advanced materials characterization tools at ORNL to study LMRNMC cathodes developed through the Vehicle Technologies Office Applied Battery 

Research program. Team members are seeking insight into correlations between cation 

ordering and voltage fade in the cathodes.

Electrochemical experiments compared data collected from pristine TODA HE5050 highvoltage cathode oxides with data from the same material after it was cycled. One cathode 

was cycled at an upper cutoff voltage (UCV) of 4.2 (2.4–4.2 V voltage window) and the other 

at a UCV of 4.8 (2.4–4.8 V voltage window). After the battery cells had cycled 125 times, the 

cathodes were harvested, washed with dimethyl carbonate, and dried. The data revealed 

voltage fade in the cell with the higher UCV but not in the cell with lower UCV.

Selected area electron diffraction (SAED) results for pristine HE5050 confirm the presence of 

cation ordering. High-resolution transmission electron microscopy (TEM) shows a 

fundamental O3 phase along with the cation-ordering peaks. Magnetic susceptibility data 

show a divergence of field cooling (FC) and zero field cooling (ZFC) at T=50°C, confirming 

the cation ordering.

SAED data from HE5050 cycled at 4.2 UCV show it retained cation ordering, and TEM 

imaging shows the O3 phase. The FC and ZFC divergence is seen in the magnetic 

susceptibility data, providing further evidence that cation ordering is retained after 125 

cycles at 4.2 V UCV. 

After 125 cycles at 4.8 V UCV, the SAED pattern shows fundamental O3 reflections, but the 

cation-ordering reflections have vanished. Instead, extra reflections between two 

fundamental O3 spots are observed; they indicate the presence of a spinel phase. The SAED 

data agree with the TEM image showing a spinel-type atomic structure. In the magnetic 

susceptibility data, the splitting of FC and ZFC (which indicates cation ordering) is not 

observed. These observations demonstrate that cation ordering is suppressed or vanishes 

after cycling at 4.8 V UCV and the spinel phase is introduced, which leads to the voltage 

fade.

After several cycles at a UCV of 4.8 (125 cycles in this study), nucleation and growth of the 

spinel phase occurs, and the structure may slowly transform to the spinel phase. 

These experiments show that structural rearrangement occurs in the LMR–NMC cathode 

only at higher potentials (e.g., 4.8 V) and indicate a direct correlation between cation 

ordering and voltage fade.
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 55

SAED, high-resolution TEM, and magnetic susceptibility data from pristine TODA HE5050 after 

125 cycles charged to UCVs of 4.2 and 4.8 V. Source: Physical Chemistry Chemical Physics

15, 19496, (2013)

Publications and Patent

1. D. Mohanty, A. Huq, E. Andrew Payzant, A. Safa-Sefat, J. Li, D. P. Abraham, D. L. 

Wood, and C. Daniel, “Neutron diffraction and magnetic susceptibility studies on a 

high-voltage Li1.2Mn0.55Ni0.15Co0.10O2 lithium-ion battery cathode: Insight into the crystal 

structure,” Chemistry of Materials 25, 4064 (2013).

2. D. Mohanty, A. Sefat, J. Li, R. A. Meisner, R. A. Justine, E. A. Payzant, D. P. Abraham, D. 

L. Wood, and C. Daniel, “Correlating cation ordering and voltage fade in a lithiummanganese-rich lithium-ion battery cathode oxide: A joint magnetic susceptibility and 

TEM study,” Physical Chemistry Chemical Physics 15, 19496 (2013).

3. D. Mohanty, S. Kalnaus, R. A. Meisner, K. J. Rhodes, E. A. Payzant, D. L. Wood, and 

C. Daniel, “Structural transformation of a lithium-rich Li1.2Co0.1Mn0.55Ni0.15O2 cathode 

during high voltage cycling resolved by in situ x-ray diffraction,” Journal of Power Sources

229, 239–248 (2013).
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56 ORNL Sustainable Transportation Program

4. D. Mohanty, S. Kalnaus, R. A. Meisner, A. Safa-Sefat, J. Li, K. J. Rhodes, E. A. Payzant, 

D. L. Wood, and C. Daniel, “Structural transformation in a Li1.2Co0.1Mn0.55Ni0.15O2

lithium-ion battery cathode during high-voltage hold,” RSC Advances 3, 7479–7485 

(2013).

5. D. Mohanty, A. Safa-Sefat, S. Kalnaus, J. Li, R. A. Meisner, E. A. Payzant, D. P. Abraham, 

D. L. Wood, and C. Daniel, “Investigating phase transformation in 

Li1.2Co0.1Mn0.55Ni0.15O2 lithium-ion battery cathode during high-voltage hold (4.5 V) via 

magnetic, x-ray diffraction, and electron microscopy studies,” Journal of Materials 

Chemistry A 1, 6249–6261 (2013).

New Solid State Sulfur-Based Battery

Contact: Claus Daniel, danielc@ornl.gov, 865-241-9521

Among known battery chemistries, lithium-sulfur (Li-S) holds the greatest promise for highenergy batteries. However, the development of Li-S batteries has been impeded by the low 

electronic and ionic conductivities of the sulfur cathode and poor cyclability of the metallic 

lithium anode. Scientists at ORNL are tackling these barriers to Li-S battery development by 

designing a battery in an all-solid-state configuration using a new family of sulfur-rich 

compounds as cathode materials. 

These new compounds contain polysulfide bonds that enable reversible energy storage and 

release and have high ionic conductivity, the key characteristic for improved cycling performance. 

To enable cycling of the sulfur cathode in a conventional Li-S battery, a liquid electrolyte 

with high polysulfide solubility must be used to overcome the poor ionic conductivity of the 

solid sulfur. This process, however, leads to intrinsically short cycle life. In addition, the 

growth of lithium metal in liquid electrolytes and the constantly growing solid electrolyte 

interphase on the anode surface further shorten the Li-S batteries’ cycle life and cause safety 

concerns. 

In the ORNL-developed solid-state battery configuration, conventional liquid electrolytes 

were replaced by a solid electrolyte with two advantages—complete elimination of the 

polysulfide shuttle and safe cycling of the metallic lithium anode. The key challenges for 

developing all-solid Li-S batteries are three requirements: (1) electrolytes with high ionic 

conductivity and excellent electrochemical stability in both the anode and cathode, (2) a cell 

design that prevents the penetration of lithium dendrites, and (3) a sulfur cathode with high 

ionic conductivity. 

The ORNL group has developed materials such as sulfide-based solid electrolytes and 

lithium polysulfidophosphate (LPSP) for solid state Li-S batteries. These materials have 

excellent compatibility with the metallic lithium anode and the sulfur-rich cathode. The key 

limitation of the sulfur cathode is its low ionic conductivity. The excellent cyclability 

demonstrated in this research is attributed to the high ionic conductivity of LPSP, which is 

10 million times higher than that of lithium sulfide (Li2S), the most conductive conventional 

sulfur cathode. A high capacity of 1,200 milliamperes per hour per gram (based on sulfur) 
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 57

was achieved for 300 cycles at 60°C for this all-solid-state battery configuration using these 

newly developed materials.

Cycling performance of an all-solid-state Li-S battery at C/10 with an LPSP sulfur cathode. 
Vehicle Technologies R&D Highlights 2013 Annual Report

58 ORNL Sustainable Transportation Program

Lightweight Materials

Online Weld Quality Monitor and Control with Infrared Thermography

Contact: Zhili Feng, fengz@ornl.gov, 865-576-3797)

ORNL researchers made significant progress toward development of an infrared (IR) 

thermography–based system to quantitatively inspect spot weld quality in real time on auto 

manufacturing lines. A nondestructive weld inspection system will help automakers 

integrate advanced high-strength steel (AHSS) and other lightweight materials into their 

products.

Resistance spot welding (RSW) is the most widely used technology for joining auto body 

components. But variations in welding conditions and part fit that occur in the high-speed 

assembly process result in imperfect joints that impair vehicle quality and performance. 

Weld quality is even more critical in joining parts made of lightweight metals. To ensure 

weld quality, the auto industry needs a nondestructive inspection system that is automated, 

fast, and low-cost and does not interfere with the automated welding fabrication process.

The nonintrusive, noncontact nature of IR thermography makes it especially attractive for 

highly automated assembly lines.

The project’s FY 2013 efforts focused on (1) refining the data analysis algorithm, (2) integrating the automated inspection software with the prototype system, and (3) validating the entire system for various welding conditions. 

Schematic of the IR thermography–based weld quality inspection system.

Additional real-time and post-weld image data were collected, mostly for boron steels of 

different grades, thicknesses, coatings, and stack-up configurations. Welding parameters 

were carefully controlled to produce welds with varying attributes (e.g., nugget size). Realtime IR images of spot welding were acquired, and the resulting welds were further analyzed using the post-weld inspection procedure.
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 59

A major technical achievement was the addition of self-learning capability to the software. 

The system can automatically generate a weld quality database based on destructively 

measured data and the welding conditions specified by users and then use it to make quantitative predictions of weld attributes. 

The research team also further refined image analysis algorithms for real-time IR inspection. 

The system can collect an image and analyze the data in 1.5–2.5 s and can positively identify 

weld nugget size, weak stuck welds, and welding expulsion. For post-weld inspection, the 

system automatically creates a weld quality database with user-provided measurement data. It collects and analyzes an image for each weld in about 3 s. Nugget size, thickness, stuck 

welds, and excessive indentation are accurately measured, and nondestructive post-weld IR 

evaluation can measure the weld nugget shape on the faying surface. 

Post-weld IR-measured weld shape vs. cross section of destructive measurement (on the faying surface): (a) good weld and (b) weld with irregular shape.

In June 2013, representatives of GM, Ford, Chrysler, and Honda attended an onsite demonstration of the IR prototype system in Detroit. The automakers and their suppliers are interested in working further with ORNL. Further system testing and refinement will be carried 

out on the production lines of Cosma’s Eagle Bend Manufacturing facility in Clinton, 

Tennessee.

Improving Fatigue Performance of AHSS Welds

Contact: Zhili Feng, fengz@ornl.gov, 865-576-3797

ORNL and steelmaker ArcelorMittal USA are working to improve the weld fatigue strength 

and durability of auto body structures made of lightweight materials such as advanced 

high-strength steel (AHSS), magnesium, and aluminum. Inadequate weld fatigue life hinders widespread use of these materials in vehicles, so improving fatigue life is critical to reducing vehicle weight. Technologies developed in this project are expected to provide costeffective, practical solutions to the auto industry.

Current weld fatigue improvement methods are based mostly on post-welding steps that 

are cost-prohibitive in high-volume manufacturing. This project focuses on developing 

methods that are integral to the welding operation. FY 2013 research focused on developing 

strategies to mitigate residual stresses in weld start and stop regions; both modeling and 

observation under test have identified those regions as the critical locations for initiation of 

fatigue cracking under cyclic loading. Two different approaches showed dramatic improvements in weld fatigue life.
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60 ORNL Sustainable Transportation Program

A weld fatigue specimen configuration was designed to mimic the stitch weld pattern typical in auto body and chassis structures. It was fabricated by placing a 50 mm long seam 

weld on the lap joint of two steel sheets—the most common weld type in vehicles. The configuration contains both weld start and stop. It maintains the weld residual stress field characteristic of actual seam welds and produces stress/strain conditions resembling those that 

cyclic loading imposes on vehicle structure welds.

The first approach explored a new low transformation temperature (LTT) filler wire design 

that considered the effect of LTT on weld residual stress and other factors such as weldability, strength, and toughness in the chemical formulation. Preliminary fatigue testing at medium load confirmed 3–5× weld fatigue improvement with the LTT filler wire. The new filler wire is also being tested under other loading levels.

In the second approach, a mechanical stress management technique was developed to mitigate tensile residual stresses in the high-stress-concentration region of the stitch weld. This 

resulted in 5–10× fatigue life improvement at the low-stress level relevant to the durability 

of auto body structures, compared with ER70-S filler wire commonly used to weld AHSS 

body structures. In fact, at 2,000 lb, the weld specimens with stress management did not 

break after 10 million cycles.

High-energy synchrotron x-ray diffraction was used to determine the weld residual stress 

and the effect of the mechanical stress management technique. The results showed the technique was indeed able to considerably lower residual stresses, providing a technical basis 

for the observed improvement in weld fatigue life.

The two approaches will be further refined and optimized and technology commercialization strategies will be formulated in FY 2014.

(c)

(a) Representative welding pattern in auto body structures, (b) special weld fatigue specimen configuration, and (c) appearance of actual weld fatigue testing specimen adopted 

in this project.
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Austenite-Ferrite Transformation Details in Carbon Steels

Contact: Zhili Feng, fengz@ornl.gov, 865-574-3797

ORNL researchers combined neutron scattering, x-ray diffraction, and numerical simulation 

to understand phase transformation behaviors during the annealing of advanced highstrength steel (AHSS) and the mechanisms governing the exceptional combination of high 

strength and ductility in multilayer composite steels.

Steel is expected to remain a primary auto body structural material for the foreseeable future. First-generation AHSS currently used in vehicles offers excellent crash management 

and other safety benefits as well as considerable weight reduction. The automotive industry, 

steel industry, and government are working together to develop third-generation AHSS that 

will offer even greater potential for weight reduction and safety enhancement, as well as 

acceptable manufacturability and affordability. These steels would have a strength-toweight ratio equal to or greater than those of aluminum and magnesium alloys.

Controlling costs will likely require that third-generation AHSSs be no more than modestly 

alloyed compared with first-generation AHSS and be capable of being produced within existing steel mills. 

Researchers used the Spallation Neutron Source (SNS) at ORNL and the Advanced Photon 

Source at Argonne National Laboratory to characterize in situ austenite–ferrite phase transformation behavior under rapid heating/cooling conditions typical of modern sheet steel 

production and to analyze the microscopic deformation and failure processes in dual-phase 

AHSS and multilayered composite steels. In FY 2013, in situ neutron experiments were conducted at SNS for various heating and cooling conditions, focusing on austenite formation 

and the effects of diffusion and homogenization of alloying elements on the transformation—a key variable in production of first-generation AHSS and in the design of some 

third-generation AHSS.

The experimental results suggest that the formation of austenite depends on both the heating rate and the initial microstructure. A phase transformation model was developed and 

applied to the steel being studied to correlate with the neutron diffraction results to provide 

a fundamental understanding of the formation of austenite in dual-phase steels.

Publications and Presentations

1. R. Barabash, O. Barabash, M. Ojima, Z. Yu, I. Inoue, S. Nambu, T. Koseki, R. Xu, and 

Z. Feng, “Interphase strain gradients in multilayered steel composite from microdiffraction,” Metallurgical and Materials Transactions A 45(1), 98–108 (2013). 

2. Z. Yu, et al. “In situ neutron diffraction study of microscopic deformation processes and 

the microstructure effect in advanced high-strength steels,” invited talk at TMS 142nd 

Annual Meeting & Exhibition, San Antonio, March 3–7, 2013. 

3. Z. Yu, R. Barabash, O. Barabash, W. Liu, and Z. Feng, “In situ probing of microscopic 

deformation kinetics in advanced high-strength steels,” poster presented at TMS 142nd 

Annual Meeting & Exhibition, San Antonio, March 3–7, 2013. First prize in Young Professional Poster Competition. 
Vehicle Technologies R&D Highlights 2013 Annual Report

62 ORNL Sustainable Transportation Program

720 740 760 780 800 820 840 860 0.0

0.2

0.4

0.6

0.8

1.0

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 As-received

Weight Fraction of Austenite

Temp (oC)

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0.2

0.4

0.6

0.8

1.0

Heat-treated 

 As-received

Weight Fraction of Austenite

Temp (oC)

(a) (b)

The effect of initial microstructure and heating rate on the nonequilibrium ferrite/martensite

(α+αM) to austenite (γ) transformation in a DP980 steel observed by in situ neutron diffraction 

measurement with (a) a 3°C/s heating rate and (b) a 30°C/s heating rate.

The effect of heating rate on the nonequilibrium phase transformation in tempered 

martensite predicted by the phase transformation model developed in this project.

IR Heat Treatment and Residual Stress Characterization of Bimetallic Joints

Contact: Tom Watkins, watkinstr@ornl.gov, 865-387-6472

An ORNL project is evaluating the use of infrared (IR) lamps for heat treatment of bimetallic 

joints to save energy, time, and processing costs in auto manufacturing. In 2014, the ORNL 

research team treated an aluminum/steel joint in a prototype IR heating furnace and modeled the effects of the heating. The team also used neutron scattering to measure the residual 

stresses in conventionally treated bimetallic joints.

Aluminum structural components are typically manufactured using a cast AlSiMg alloy and 

then heat-treated to achieve the desired mechanical properties. The heat treatment processes 

(T5 and T6) have long thermal cycles that are energy-intensive and costly. The T6 process 

incorporates a water quench, which imposes corrosion and residual stress concerns for 

bimetallic components. The ORNL project aims to develop and model an IR heat treatment 

process for an aluminum casting with a bimetallic joint that produces a T5 temper in less 
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 63

time than conventional processing, and to develop a modified T6 process for improved 

mechanical properties without any loss of joint integrity. The project focuses on a specific 

application, but the methods developed are applicable to multiple joints on many vehicle 

platforms.

ORNL’s prototype IR electric furnace was used to heat an AlSiMg alloy component with an 

AlSiMg/steel joint. The furnace contains tungsten–halogen lamps located above and below 

the aluminum component to equalize the temperature distribution within it. A CAD model 

was used to study the effect of IR heating on temperature and stress distributions within the 

part. A heat transfer model of the part was completed and a stress analysis model developed in ABAQUS. The temperature distribution in the steel portion of the joint during heating was simulated. The thermomechanical model to predict residual stress used a rateindependent isotropic hardening plasticity model for the steel. Temperature-dependent 

property data were used for properties for both materials.

As residual stresses play an important role in these joints, the team used neutron diffraction 

at ORNL’s High Flux Isotope Reactor to measure and map residual stresses in a series of 

conventionally heat-treated joints. Residual stresses were measured in both the steel and 

aluminum in the radial, hoop, and axial directions.

The results of the ORNL research indicate that IR heat treatment can significantly improve

the mechanical properties of bimetallic components and maintain the necessary residual 

stresses without water quenching. It also reduces process time and cost.

(a) (b)

Temperature (°C) distribution for the steel portion of the joint. (a) The front surface is the 

symmetry plane; the top surface is shown facing the IR heat source. (b) Stress distribution (Pa) 

through a vertical cross-section of the steel near the edge for the hoop stress component 

(deformation magnification 3 times ).

Presentations

1. T. R. Watkins, A. S. Sabau, H. Yin, D. L. Erdman III, W. Zhang, T. W. Skszek, and X. Niu,

“Residual stress determination in cast bi-metallic joints,” presented at TMS 2013 Annual 

Meeting, San Antonio, March 6, 2013.

2. H. Yin, A. S. Sabau, G. M. Ludtka, T. W. Skszek, and X. Niu, “Yield strength prediction 

for rapid age-hardening heat treatment of aluminum alloys,” presented at TMS 2013 

Annual Meeting, San Antonio, March 5, 2013.

Hoop stresses
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64 ORNL Sustainable Transportation Program

3. H. Yin, A. S. Sabau, T. W. Skszek, and X. Niu, “Microstructure evolution modeling for 

solution treatment of aluminum alloys,” presented at TMS 2013 Annual Meeting, San 

Antonio, March 5, 2013.

ORNL Commissions Carbon Fiber Technology Facility

Contact: Lee McGetrick, ORNL, mcgetricklb@ornl.gov, 865-574-6549

The Carbon Fiber Technology Facility (CFTF) at ORNL was commissioned for operations in 

March 2013, 6 months ahead of schedule and almost $2 million under budget. DOE selected 

ORNL to build and operate the CFTF under a competitive call for proposals for a highly 

flexible pilot-scale low-cost carbon fiber facility to demonstrate and evaluate affordable new 

manufacturing technologies. Construction began in March 2011.

CFTF has a unique carbon fiber line for demonstrating advanced technology scale-up and 

producing market-development volumes of prototypical carbon fibers. It has the capability 

and flexibility—unmatched anywhere in the world—to process a range of feed stocks and 

product forms. CFTF bridges the gap between laboratory research and commercial-scale 

deployment of low-cost carbon fiber technologies, filling a critical need to promote industrial competitiveness for the manufacture of carbon fiber in the United States.

Co-funded by VTP and the Advanced Manufacturing Office, the project supports EERE efforts to transition technologies to industry—specifically cost-effective carbon fiber for composite materials in high-volume energy applications.

Since beginning operation, CFTF has met or exceeded goals for safe, efficient, compliant operation and production of low-cost carbon fibers. During its first year, the facility exhibited a 

perfect record of safety and environmental compliance. A process was implemented in June 

2013 by which these lower-cost carbon fibers and other products such as oxidized polyacrylonitrile fibers can be placed in the hands of industry for the development of prototypical 

composite applications to prove value of the fibers.

Successful commercialization of low-cost carbon fiber technology for energy and economic 

benefits to the United States is the overarching CFTF objective. Notable progress is being 

made in converting textile acrylic fibers supplied by the Kaltex Group, a large textile fiber 

producer in northern Mexico. Between July 8 and September 20, 2013, eight production lots 

of oxidized acrylic and carbon fibers were produced from the Kaltex precursor material. Results from these production runs indicate increasingly improved properties in tensile 

strength and modulus, suggesting the material may be a good candidate for full-scale production of lower-cost carbon fibers. The project shows that a low-cost carbon fiber can be 

produced from a textile-grade acrylic fiber and has resulted in many inquiries from industry 

partners.

Plans are to scale up the use of other alternative precursor materials, including lignin-based 

carbon fibers, cellulosic paper carbon materials, and polyolefin-based carbon fibers.
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Large carbon fiber tow in production at the Carbon Fiber 

Technology Facility using a textile-grade acrylic fiber.

Presentations

1. L. B. McGetrick and C. D. Jackson, “The human factor in carbon fiber manufacturing,” 

presented at Carbon Fibers 2012 Conference, San Diego, December 5, 2012. 

ORNL Team Pursues Energy-Efficient Advanced Carbonization Technology

Contact: Felix Paulauskas, paulauskasfl@ornl.gov, 865-576-3785

A project at ORNL’S Carbon Fiber Technology Facility (CFTF) seeks to demonstrate and 

eventually commercialize a revolutionary energy-efficient advanced conversion technology. 

Co-funded by VTP and the Advanced Manufacturing Office, this technology enables the 

manufacturing of carbon fiber that is technically and economically viable in industrial markets. Lower-cost carbon fibers are attractive for many industrial applications critical to efficient energy production and use (e.g., in transportation, wind energy, infrastructure, and oil 

drilling) that do not require aircraft-grade carbon fiber. 

The advanced conversion process is based on previous ORNL work in microwave-assisted 

plasma (MAP) and related technologies for carbonization. ORNL previously demonstrated 

that microwave energy combined with plasmas can be used to rapidly convert polyacrylonitrile precursor fibers into finished carbon fibers. The researchers demonstrated a residence 

time of approximately one-third to one-half of the conventional residence time.

The technology development team recently completed modifications and upgrades to the 

MAP line that enable it to process five tows continuously and demonstrate a >2-hour stable 

run. Mechanical properties meeting program requirements (250 KSI strength, 25 MSI modu-
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66 ORNL Sustainable Transportation Program

lus) have been achieved, but uniformity limitations and tow-to-tow energy distribution 

within the chamber resulted in higher property variability than the targets allow. 

Guided by modeling results, the team implemented significant changes to the fiberhandling equipment, achieving enhanced tensioning control and improved tow-to-tow energy distribution. The changes included horizontal tow spacing with vertical energy introduction and nonlinear tow orientation in the processing chamber. Additionally, the team 

developed an alternative technique for focusing and controlling microwave energy deposition in the processing chamber. Preliminary results show substantial energy efficiency improvements and indicate that the technique can be deployed easily on a larger scale. It likely 

will make unnecessary the common industrial practice of separating low- and hightemperature carbonization approaches. 

Appropriate tools to assist with hardware development include a system model complemented with dielectric measurement capability as a function of temperature. Optimization 

of plasma parameters for conversion will continue focusing on improving process economics and uniformity, because the process has been shown capable of meeting performance 

targets. The team will continue to review energy balance data to refine the data and prioritize remaining projects. Progress continues on improvements to the current hardware transition regions, sealing approaches, and effluent handling.

The MAP line exit feedthroughs 

are fully strung with five tows in 

the horizontal configuration.

Improved microwave energy and enhanced plasma 

hardware. This approach, demonstrated here with a 

single unit, should allow improved energy deposition 

control for industrial scale-up.

Advanced Oxidative Stabilization of Carbon Fiber Precursors

Contact: Felix Paulauskas, paulauskasfl@ornl.gov, 865-576-3785

The cost of producing carbon fiber (CF) is the single most important factor controlling its 

incorporation in future automotive systems. Significant effort is being expended to develop 

enhanced production technologies, such as a higher-speed, lower-cost oxidative stabiliza-
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tion process and a higher-speed microwave-assisted plasma (MAP) process carbonization 

method. 

Conventional oxidation is a slow thermal process that typically consumes more than 80% of 

the processing time in a conventional CF conversion line. A rapid oxidation process could 

dramatically increase conversion line throughput and appreciably lower the fiber cost, so 

researchers are working to develop an atmospheric plasma processing technique to rapidly 

and inexpensively oxidize polyacrylonitrile (PAN) fibers. 

Atmospheric pressure plasma is a new high-rate technology for use in industrial processes. 

A related project has already demonstrated the potential for significantly accelerating carbonization. The oxidation residence time must be greatly reduced to effect fast conversion 

and match the speed of the advanced carbonization technology. This project is developing 

an atmospheric plasma oxidation technology that could be used in line with conventional 

conversion equipment or integrated with other advanced fiber conversion processes to produce low-cost CF for the automobile industry. This effort is aimed at further developing 

those technologies to be able to continuously process multiple 12–50K tows of fiber and 

achieve properties meeting minimum property requirements with tow-to-tow and alongthe-tow property variation within ±15%. The goals also include significantly reducing the 

time required for oxidative stabilization by 2–3 times (conventionally 90–120 min), which 

will permit greater fiber production rates and improved economics.

The technology has been proved at the laboratory scale and is now being scaled to the pilot 

scale. Later it will be scaled to the pre-production scale in collaboration with industrial partners. The research team is working to establish a clear path of technology transfer to industry by the end of FY 2014. By the end of FY 2015, researchers project that they will be ready 

to procure, install, test, and operate a pilot-scale (25 ton/year) plasma oxidation module in 

an advanced technology pilot line. The next step will be the design and construction of an 

advanced technology pilot line installed at ORNL’s Carbon Fiber Technology Facility. It will 

be used to validate system performance and scalability as well as produce the required 

quantities of advanced-technology CFs to support the Lightweight Materials Program’s advanced development activities.

Single-filament cross section during conventional oxidative stabilization process.

1 when t ≈ 0

 

 
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68 ORNL Sustainable Transportation Program

Mechanical properties of plasma oxidation vs. conventionally carbonized PAN fiber. Oxidation residence time was 30 min for aerospace, 33 min for textile-grade PAN.

Understanding Protective Film Formation by Magnesium Alloys in Automotive 

Applications

Contact: Kinga A. Unocic, unocicka@ornl.gov, 865-574-0996

ORNL is using advanced characterization methods to gain insight into the formation of protective films on magnesium (Mg) alloys, with the ultimate goal of permitting more widespread use of these alloys in vehicles.

Mg alloys offer low density, good strength, amenability to casting, and ease of recycling, but 

their high susceptibility to corrosion is a barrier to widespread adoption in auto manufacturing. A key factor in the lack of corrosion resistance is that Mg alloys do not establish a 

continuous, fully protective surface film under many exposure conditions. Alloying and/or 

conversion coatings have been shown to modify surface film performance; however, a detailed understanding of how and why is currently lacking.

This project seeks to provide a detailed nanoscale picture of the structure and composition 

of corrosion films on Mg alloys as a function of alloy content and exposure conditions. Mg

alloys are notoriously difficult to work with because of their high reactivity, so development 

of appropriate sample preparation and characterization techniques is essential. 

Techniques being evaluated include (1) in-situ focused ion beam (FIB) milling as a sample 

preparation method and transmission electron microscopy (TEM) analysis of the surface 

film cross-section to determine film morphology and nanoscale segregation of alloy additions, (2) secondary ion mass spectrometry (SIMS) tracer studies of Mg alloys/coatings to 

understand growth mechanism(s) and hydrogen and oxygen uptake into corrosion films, (3) 

neutron scattering of Mg alloy surface film nanoporosity and hydrogen species incorporation, and (4) atom probe tomography (APT) to provide 3-dimensional quantification of 

chemistry at the atomic scale at the film and alloy–film interface.

Advanced TEM sample preparation and characterization methods developed in FY 2012 were 

successfully applied in FY 2013 to study aqueous film formation on Mg alloys as a function of 

exposure time and alloying additions. After a sample of the widely used commercial alloy 

AZ31B was immersed in water for 24 h, a partially hydrated MgO base film several hundred 
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nanometers thick was formed on its surface. Some porosity was evident, and an underlying 

thin area at the film–metal interface indicated heavier element segregation. Energy-dispersive 

spectroscopy x-ray analysis (maps and line profiles) showed aluminum presence throughout 

the entire film thickness and zinc enrichment at the metal–film interface. 

Compared with film formation and corrosion on high-purity Mg controls, the nanoscale 

segregation of aluminum and zinc into the film and the metal–film interface regions on 

AZ31B is believed to slow the film growth rate and improve corrosion resistance. The baseline water film growth behavior will be used for SIMS isotopic tracer studies, neutron scattering, and APT in FY 2014, and as a baseline condition to analyze the effects of varying alloy additions and exposure conditions.

AZ31B

Pores

b) Al Mg Zn

a)

O

(a) High angle annular dark-field scanning TEM image of the film cross-section formed on 

AZ31B after 24 h immersion in water. (b) EDS x-ray maps of Al, O, Mg, and Zn acquired from 

the region marked with the box in (a).

Publications and Presentations

1. K. A. Unocic, H. H. Elsentriecy, M. P. Brady, H. M. Meyer III, G.-L. Song, M. Fayek, R. A. 

Meisner, and B. Davis, “Transmission electron microscopy study of aqueous film formation and its evolution with time on magnesium alloys,” submitted to Corrosion Science

in 2013.

2. K. A. Unocic, H. H. Elsentriecy, M. P. Brady, G.-L. Song, H. M. Meyer III, J.R. Keiser, 

L.M. Anovitz, G. Rother, J.K. Thomson M. Fayek and B. Davis, “Characterization of film 

formation on commercial and model magnesium alloys,” presented at Magnesium 

Technology 2013 Symposium at 2013 TMS Annual Meeting, San Antonio, March 4, 2013. 
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3. H. H. Elsentriecy, K. A. Unocic, M. P. Brady, G.-L. Song, H. M. Meyer III, J.R. Keiser, 

L.M. Anovitz, G. Rother, J.K. Thomson M. Fayek and B. Davis, “Characterization of film 

formation on commercial and model magnesium alloys,” presented at Meet the candidate Poster Session Symposium at 2013 TMS Annual Meeting, San Antonio, March 4, 

2013. 
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Power Electronics and Electric Motors

10 kW Wide Bandgap Device-Based Inverter

Contact: Madhu Chinthavali, chinthavalim@ornl.gov, 865-946-1411

ORNL researchers have developed a highly efficient silicon carbide inverter for use in 

electric vehicles that offers protection against high temperatures and operating frequencies 

while reducing system costs.

Power electronics systems on hybrid, plug-in hybrid, and all-electric vehicles impose harsh 

environmental requirements on electrical components. Costly thermal management systems 

are necessary to avoid device failures, because these vehicles operate at high temperatures. 

At the same time, the pressure to keep costs reasonable for such vehicles is resulting in 

designs that use less hardware. These design changes offer the added benefits of lighter 

weight and greater efficiency.

Emerging wide bandgap (WBG) devices are poised to offer significant improvements in 

power electronics for hybrid, plug-in hybrid, and electric vehicles. WBG devices can operate 

with enhanced efficiency over higher temperatures and operational frequencies. These 

characteristics lead to reduced cooling requirements and minimized passive component 

requirements, providing vehicle designers with opportunities for revolutionary strides in 

power electronics. The characteristics of two particular compounds—silicon carbide and 

gallium nitride—enable the development of smaller, more efficient, robust power electronics 

in a multitude of clean energy applications.

Following a review of a third-party analysis of WBG devices from multiple vendors, 

researchers at ORNL developed a 10 kW all-silicon carbide inverter using commercially 

available modules. Gate drivers from Rohm were used in the inverter, which measures 226 

× 224 × 73 mm. The gate driver is equipped with galvanic isolation up to 3,000 Vrms and 

features integrated overcurrent protection, undervoltage lockout, and temperature 

feedback. The modules are mounted on a commercial heat sink with thermal grease as the 

medium of heat transfer from the lower side of the power modules. This prototype model 

will be packaged so that controls and capacitors are close to the heat sink. The small 

individual capacitors used in a series will ensure better cooling and reduced costs.

Inverter test results indicate the overall inverter efficiency is about 98% under various

operating conditions. These results will be used as a benchmark for development of a nextgeneration inverter that will be built using an ORNL-developed WBG package. The results 

indicate that the inverter will meet DOE’s 2020 inverter targets if it is scaled to 30 kW. In 

addition, WBG technology will aid developers in achieving targets for volume, efficiency, 

power density, and system costs established through U.S. DRIVE, a government–industry 

partnership focusing on research and innovation for vehicle efficiency and energy 

sustainability.
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Prototype of a 10 kW silicon 

carbide inverter.

(Left) Inverter efficiency vs. output power at 325 Vdc, 4 kHz switching, and 60°C 

coolant with a flow rate of 1.5 gal per min. (Right) Inverter efficiency changes only 

slightly as switching frequency increases.

Advanced All-SiC Automotive Power Electronics Module

Contact: Zhenxian Liang, liangz@ornl.gov, 865-946-1467

ORNL is developing advanced wide bandgap (WBG) automotive power electronics 

technologies to help achieve DOE Advanced Power Electronics and Electric Motor Program 

targets. This effort involves multidisciplinary capabilities including packaging development 

and characterization; thermal, electrical, and thermomechanical expertise; and reliability, 

process and manufacturing considerations.

A prototype of an all-silicon carbide (SiC) 100 A/1,200 V phase-leg power module was 

fabricated in-house at the ORNL Packaging Laboratory. The module is composed of the 

latest industrial SiC power devices, a metal oxide semiconductor field effect transistor 

(MOSFET), and a junction barrier Schottky diode. It also features second-generation thermal 

packaging, allowing integrated direct cooling. Combining the superior attributes of SiC and 

packaging advancements, this module allows much higher efficiency and higher-density 

power conversion.
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Prototype of all-SiC 100 A/1200 V phase-leg power module with integrated mini-cooler 

(left). Schematic of its thermal package (right).

The module was comprehensively characterized and compared with its silicon (Si) 

counterparts in an insulated gate bipolar transistor (IGBT)/PiN diode module with the same 

rating. The SiC MOSFET allowed reductions of 45% in die area, 25% in voltage drop (at 

40 A), and 78% in switching power losses. The specific thermal resistivity of the integrated 

cooling package is more than 33% lower than that of a conventional (first-generation) 

package. 

The allowed current density for a 100°C temperature increase is 66 A/cm2 to 185 A/cm2 for 

the different packages. The die area can be reduced by from 1.9 to 2.2 times by changing 

from Si IGBTs to SiC MOSFETs and by 1.3 to 1.5 times by using the second-generation 

cooling configuration rather than the conventional design.

The module’s performance improvements enable system operation at efficiencies and 

frequencies beyond the Si limits. This module is a significant stride toward achieving DOE’s 

power density and cost targets for power electronics systems.

Publications and Presentations

1. Z. Liang, “Development of advanced all-SiC power modules,” IEEE Transactions on 

Power Electronics, Special Issue on WBG Power Devices and Their Applications, 29(5), 

2289–2295 (May 2014). 

2. Z. Liang, P. Ning, and F. Wang, “Advanced packaging of SiC power module for 

automotive applications,” Proceedings of the Fifth IEEE Energy Conversion Congress and 

Exposition, Denver, September 15–19, 2013.

3. Z. Xu, M. Li, F. Wang, and Z. Liang, “Investigation of Si IGBT operation at 200°C for 

traction applications,” IEEE Transactions on Power Electronics 28(5), 2604–2615 (May 

2013).

4. P. Ning, Z. Liang, and F. Wang, “Double-sided cooling design for novel planar module,” 

Proceedings of the IEEE Applied Power Electronics Conference and Exposition, Long Beach,

Calif., March 17–21, 2013.
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Development of Low-Loss Motor Lamination Steel

Contact: Burak Ozpineci, burak@ornl.gov, 865-946-1329

Electric traction drive systems (ETDSs) account for 16% of overall losses in all-electric 

vehicles over an Urban Dynamometer Driving Schedule drive cycle. Most of these losses are 

accumulated in the traction motor. For example, the 2012 Nissan LEAF ETDS has a lineaveraged efficiency of 92.5%, the combined result of 95.2% traction motor efficiency and 

97.2% inverter efficiency. Therefore, ETDS efficiency improvements are focused on motor 

materials that have the potential to significantly reduce core losses. ORNL has developed a 

novel processing method for a high-silicon steel that exhibits both low losses and reduced 

cost.

Static and dynamic tests comparing a high-silicon steel with a production lamination core

steel confirmed the low-core-loss benefits of high-silicon blends. A grade 29M19C5 steel, 

which contains 2.67% silicon (per ASTM A677 36F155 for 0.36 mm M19), was compared 

with JFE 10JNEX900 (JFE SupercoreTM), which contains 6.5% silicon, the highest percentage 

of silicon used in steel.

The commercial 6.5% silicon steel is produced by chemical vapor deposition (CVD). It has 

low core losses but is very expensive. ORNL has pursued a novel processing technique

based on strain softening during warm deformation (first reported by Chinese researchers) 

that effectively destroys lattice ordering (the B2 phase), leading to restoration of ductility 

and subsequent ease of cold formability. The ORNL process leads to low-cost Fe-6.5% Si 

steel sheet for motor laminations with magnetic properties equal to or better than those of 

the JFE 10JNEX90 produced by CVD. 

Scaleup and commercialization of the alternative process is important to industry and motor 

manufacturing because of the major cost reduction. More development of the alternative 

production process is needed, specifically in the optimization of boron content and the 

thermomechanical process parameters. ORNL is exploring superimposed ultrasonic 

vibration during deformation as a means of eliminating the need for warm rolling.

Comparison of core-only losses for the various materials at full 

rotor flux vs. speed.

Production IPM Core

Fe 6.5% Si Core

-86%
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Work softening at ORNL of Fe–6 wt % Si–500 ppm B during warm 

compression at 400°C.

Multiple Isolated Flux Path Switched Reluctance Motor

Contact: Timothy Burress, burressta@ornl.gov, 865-946-1216 

The simplicity of switched reluctance (SR) motors results in many benefits related to cost, 

reliability, and manufacturability. A novel SR motor design developed at ORNL addresses 

issues with these motors and offers a cost-effective, competitive alternative to permanent 

magnet motors made with rare earth materials, which have incurred significant price 

volatility in recent years.

Torque ripple and acoustic noise are the primary negative characteristics of SR motors, 

particularly when they are considered as an alternative to permanent magnet motors in 

passenger vehicles. Therefore, reluctance motors with multiple isolated flux paths (MIFPs) 

were developed by ORNL to facilitate better control over torque ripple and acoustic noise 

and achieve a secondary goal of improving power density and specific power. The 

segmented MIFP SR motor design introduces the potential to locate teeth within closer 

proximity to each other, thereby facilitating torque ripple reduction while maintaining 

magnetic saliency, which is the fundamental method of producing torque in SR motors.

Many MIFP variants were researched. The first-generation SR motor design consists of six 

segmented stator pieces forming 12 stator teeth with a conventional SR rotor with 10 teeth. 

The use of segmented stator pieces opens up many design opportunities that can lead to 

increased power density and/or reduced torque ripple and acoustic noise. One primary 

advantage is the capability to use yoke-wound stator coils. Although the use of this winding 

technique may seem insignificant, a closer look reveals the following benefits:

• Winding manufacturability—Stator pieces can be wound before installation.

• Improved heat transfer—Copper, which transfers heat about 40 times better than steel, 

is located on the outer perimeter of the motor and is well suited for interfacing with a 

heat exchanger. This will increase continuous operation capabilities.

• Broad teeth—Increased overlap of torque production among phases can reduce torque 

ripple and acoustic noise.
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76 ORNL Sustainable Transportation Program

• Increased fill factor—Slots contain only one coil instead of two, thereby eliminating issues with interference between coils.

• Noise damping—Voids between stator pieces can be filled with damping material.

Hardware for ORNL’s first MIFP SR motor prototype (left) and nearly assembled 

motor with yoke-wound stator coils (center). Finite element analysis model of 

second generation MIFP SR motor (right).

A second-generation MIFP SR motor design is under way, using custom design 

optimization and simulation tools (developed during first-generation design) to produce a 

motor suitable for electric vehicle applications. So far, simulations indicate that a Nissan 

LEAF–sized MIFP SR motor can produce a peak power of 95 kW, which satisfies DOE’s 

2015 targets and is higher than the published peak power of 80 kW for the LEAF. Efforts to 

improve continuous power capability and further reduce acoustic noise are ongoing.
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Propulsion Materials

Studies Confirm Catalytically Active Single Platinum Atoms

Contact: C. K. Narula, narulack@ornl.gov, 865-574-8445

Modern characterization tools have confirmed the presence of a significant fraction of active 

metal as single atoms and 10–20 atom rafts in a fully formulated supported noble metal 

catalyst. The catalytic activity of single atoms was only recently confirmed in studies at 

ORNL.

Because supported single atoms cannot engage in catalysis via a conventional LangmuirHinshelwood (L-H) pathway, their participation in catalysis was uncertain. Recent literature 

showed that single supported atoms are indeed catalytically active, provided the support 

can participate in catalysis (e.g., CeOx and FeOx as oxygen sources) to enable L-H pathway. 

An automotive emission treatment catalyst generally contains single supported platinum 

(Pt) atoms, 10–20 atom rafts, and fully formed Pt particles supported on γ-alumina, an inert 

substrate that cannot participate in the catalytic process. In first principles theoretical 

modeling work at ORNL, researchers showed that single atoms of Pt group metals (Ni, Pd, 

and Pt) supported on θ-alumina are in zero oxidation state. Researchers also proposed that 

these single supported atoms will be catalytically active because the metal atoms in these 

systems are isoelectronic with (Ph3P)2M, a catalytically active organometallic compound.

Characterization by aberration-corrected electron microscopy, extended x-ray absorption 

fine structure, and x-ray near edge structure shows that the ORNL sample contains monodisperse single supported Pt atoms on θ-alumina. The CO oxidation occurs on this catalyst 

with a turnover frequency of 18.7×102 (s-1) measured at 20% CO conversion at 251°C, 

suggesting it is a highly active catalyst. 

A CO oxidation pathway on single supported platinum atoms (left) and aberrationcorrected electron microscopy images of 0.18% platinum on θ-alumina (right).

Since an L-H pathway is not possible on a single supported Pt atom, researchers proposed a 

CO oxidation pathway inspired by organometallic chemistry of isoelectronic (Ph3P)2Pt 

species. The first principles study showed that CO oxidation occurs via formation of 
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78 ORNL Sustainable Transportation Program

carbonate species whose decomposition is endothermic. This suggested that the catalyst 

surface will become covered with CO3 during oxidation, and the reaction will stop unless 

external energy is supplied to decompose the CO3 species. Diffuse reflectance infra-red 

spectroscopic monitoring of species of the catalyst surface during CO oxidation reaction (as 

a function of temperature) provided evidence for the formation of CO3 at room temperature. 

This research shows that single supported Pt atoms are indeed catalytically active species 

that can participate in emission treatment rather than being spectators to the catalytic 

process while waiting to become part of a fully formed Pt particle via sintering. These 

results also suggest that Pt rafts, which are accumulations of single Pt atoms bonded via 

oxygen, can participate in catalytic processes.

Publications

1. C. K. Narula and G. M. Stocks, “Ab initio density functional calculations of adsorption 

of transition metal atoms on θ-Al2O3 (010) surface,” J. Phys. Chem. C 116, 5628 (2012). 

2. C.K. Narula, et al., “CO oxidation on supported single Pt atoms: Experimental and ab 

initio density functional studies of CO interaction with Pt atom on θ-Al2O3 (010) surface,” J. Am. Chem. Soc. 135, 12634 (2013). This paper was highlighted in Nature Chemistry

5, 809 (2013).

Electron Microscopy for Characterization of Catalyst Microstructure

Contact: Larry Allard, ORNL, allardlfjr@ornl.gov, 865-607-1144

Researchers at ORNL are exploring new in situ electron microscopy techniques for ultrahigh-resolution imaging of catalytic materials in gaseous environments to study the 

reduction of NOx automotive emissions. 

ORNL partnered with the microscopy company Protochips to expand its capabilities for in 

situ reaction studies with a unique gas-cell reactor system for ORNL’s aberration-corrected 

electron microscope. The ORNL team is using a generation 3 (Gen 3) gas-cell holder for 

atomic imaging of catalysts at elevated temperatures and at gas pressures up to a full 

atmosphere. These are being used to study “self-regenerating” catalysts for emission 

reduction in partnership with Ford Research Laboratory and the University of Michigan. 

The researchers are also developing and using a Gen 4 holder and computer-controlled gas 

manifold, the basis for a commercial in situ gas reaction system for Protochips.

Microscopy gas-reaction experiments on catalyst powder materials were used to study 

redox reaction dynamics at conditions that mimicked ex situ studies conducted at the 

University of Michigan on model single-crystal perovskites with deposited precious metals. 

The reaction in the platinum-based catalytic trap oxidizer system proved to be asymmetric: 

metal extruded from the oxide within several seconds upon reduction but dissolved back 

into the support only after hours of aggressive oxidation. Finer particles dissolved more 

readily than larger particles. Many of the particles that formed during the reduction cycle 

were located in the interior of the crystal support and were not available for the catalytic 

process.
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Example of in situ reaction sequence from the platinum–catalytic trap oxidizer work. 

(a) As-prepared (oxidized condition) sample shows only a few nascent platinum 

particles. (b) First reduction condition (800°C, 10 min) shows more particles, including 

some clearly on the surface (arrows). (c) After several oxidation cycles from 450 to 

800°C for more than 2 h, many larger particles remain, but the original surface particles 

are apparently redissolved.

ORNL’s experience with the Gen 3 reactor holder, and gradual development and 

modification of the ORNL gas manifold system to allow precise control of gas pressure and 

flow conditions, enabled Protochips to produce the Gen 4 gas cell holder and gas manifold. 

It offers four electrical leads rather than two, and the leads are specially fabricated with a 

proprietary “flexicable” design for proper electrical insulation and contact pads. These 

ensure easy loading of the heater and lower window devices when the cell is built for in situ 

experiments.

Comparison of interior geometry of Gen 3 (left) and 

Gen 4 gas cell holders with four-contact “flexicables.”

The Gen 4 gas cell will be interfaced with a Protochips-fabricated gas manifold operated via 

computer control that allows remote programming and operational control capabilities for 

all valves, pumps, gas supply, gauges, and heater power. The system will be delivered and 

tested at ORNL during FY 2014.
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80 ORNL Sustainable Transportation Program

Publications

1. L. Allard, S. Overbury,W. Bigelow, M. Katz, D. Nackashi, and J. Damiano, “Novel 

MEMS-based gas-cell/heating specimen holder provides advanced imaging capabilities 

for in situ reaction studies,” Microsc. Microanal. 18, 656–666 (2012).

2. L. Allard,J. Wittig, M. Chi, K. More, W. Bigelow, J. Damiano, and D. Nackashi, “Novel 

closed-cell gas-reaction holder allows characterization of behavior of bimetallic 

nanoparticles under elevated temperatures and gas pressures,” Micros. Microanal. 

(Suppl. 2) August (2013).

3. L. Allard,W. Bigelow, J. Damiano and D. Nackashi, “Operational parameters of a 

MEMS-based closed cell gas-reaction holder for in situ atomic-level STEM imaging at 

elevated temperatures and pressures,” abstract for program of Microscopy Society of 

America Pre-Meeting Congress on Electron Microscopy in Liquids and Gases, 

Indianapolis, August 2013.

4. X. Pan, M. Katz, B. Li, X. Du, K. Zhang, Y. Duan, L. Allard, L. Chen, A. Van der Ven, and 

G. Graham, “Understanding behavior of self-regenerative catalysts by transmission 

electron microscopy and density functional theory,” Micros. Microanal. (Suppl. 2) August 

(2013).

Computational Modeling Assists Development of New Valve Alloys

Contact: Govindarajan Muralidharan, muralidhargn@ornl.gov, 865-574-4281

Several strategies such as lean-burn operation, high levels of exhaust gas recirculation, turbocharging, variable valve actuation, and variable compression ratios are being pursued to 

improve engine combustion efficiency. Exhaust gas temperatures are projected to increase 

from 760°C to at least 870°C (and possibly as high as 1,000°C) as engine efficiencies increase. 

However, strategies that retain more heat in the exhaust gas to improve efficiency result in 

increased operational temperatures for components in the exhaust path, such as valves. A

major barrier to this design route is the availability of affordable materials with adequate 

high-temperature mechanical properties and oxidation resistance.

ORNL researchers used a “materials-by-design” approach with synergistic computational 

and experimental aspects to develop cost-effective nickel-based alloys for use at higher temperatures. High-temperature fatigue strength was identified as a critical factor in determining the performance of these alloys in valve applications. Understanding the strengthening 

mechanisms in existing commercial alloys was required to enable the use of computational 

modeling to develop materials with improved properties and lower cost. A range of nickelbased alloys with potentially varying fractions of the γ’ strengthening phase were identified 

to correlate fatigue properties with the microstructures of the alloys.

Nine commercial nickel-based alloys including Alloy 751 (alloy currently used for valve applications), with Ni+Co contents ranging from 66 to 76 wt %, were selected to study the microstructures that resulted in the best fatigue properties. The results of thermodynamic calculations showed that all the alloys have a matrix of γ with the major strengthening phase as 

γ’. One or more carbide phases such as M23C6, MC, and M7C3 may also be present. The pri-
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ORNL Sustainable Transportation Program 81

mary differences between the microstructures were the weight percent of the γ’ phase at a 

given temperature and the highest temperature at which the γ’ phase is stable. 

Using the microstructures of these alloys as a target, researchers used computational thermodynamics to design new alloys with microstructures that resulted in high-temperature 

tensile and fatigue properties similar to or better than those of the commercial alloy used 

currently in exhaust valve applications. In contrast to the commercially available alloy with 

Ni+Co contents above 66 wt %, the Ni+Co content in these newly identified candidate alloys 

was lower than 50 wt %, resulting in reduced materials cost. These new alloys not only will

enable the development of exhaust valves that can operate at much higher temperatures,

but also will do so at potentially lower cost, facilitating the deployment of higher-efficiency 

vehicles. 

Thermally Conductive Epoxy Molding Compound

Contact: Andrew Wereszczak, wereszczakaa@ornl.gov, 865-576-1169

ORNL is exploring ways of improving the thermal conductivity of epoxy molding 

compounds (EMCs) used to package and insulate electronic components in automotive 

applications. Research in this project demonstrated the effectiveness of low-cost magnesium 

oxide filler in improving the thermal management capability of EMCs.

Desired EMC characteristics include electrical insulation, a low thermal expansion 

coefficient (to avoid damage from thermal cycling to internal parts encapsulated with the 

EMC), mechanical robustness and resistance to moisture absorption to protect from exterior 

environments, resistance to degradation on exposure to high temperatures, and 

insusceptibility to electric and magnetic fields.

An important limiting factor of traditional (composite) EMCs is their low thermal 

conductivity (κ), which limits options for thermal management for the electronic 

components they protect. Because the epoxy is the continuous phase in the EMC composite 

structure, it also has a low κ (typically κ ~ 0.2–0.3 W/mK). However, EMCs can be 

engineered for higher κ with an appropriate choice of filler material and control of its 

content. Doing so with a low-cost filler was the focus of this project. 

For example, the use of a hypothetical EMC with a thermal conductivity of 3–5 W/mK in 

combination with active cooling can substantially lower the maximum temperature of the 

constituent packaged in the material. Using an EMC with 3–5 W/mK can lower junction 

temperature by tens of degrees. Such a temperature reduction can improve device longevity 

and performance and enable the use of additional means of cooling and potentially more 

space- and weight-efficient redesigns of electronic and motor components.

Magnesium oxide has an attractive combination of characteristics as a filler in epoxy. It is an 

inexpensive compound with a relatively high bulk thermal conductivity. Another unique 

and attractive characteristic is it has low hardness and abrasiveness, which reduce mold 

fixture wear during EMC molding.

The significant outcome of this study was the demonstration that a bulk thermal 

conductivity of up to 3 W/mK can be achieved at low cost if MgO is used as a filler in an 
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82 ORNL Sustainable Transportation Program

EMC. This is a tenfold increase in thermal conductivity compared with unfilled epoxy and 

about two times the κ of traditional (SiO2-filled) EMCs. The results signify that MgO-EMCs 

would be much more effective than traditional EMCs at lowering the maximum 

temperature of encapsulated components while having equivalent cost.

Because of the attractive performance of this new MgO-EMC, a potential large-scale EMC 

manufacturer is considering it as a commercial product, and engineers are considering its 

use in new power electronic and electric motor applications.

Temperature distribution and maximum 

temperature modeled in a hypothetical power 

module encapsulated by an EMC material with 

different thermal conductivities. A larger thermal 

conductivity decreases the maximum 

temperature of the module.

Publication and Invention Disclosure

1. A. Wereszczak, T. G Morrissey, C. N. Volante, P. J. Farris, Jr., R. J. Groele, R. H. Wiles, 

and H. Wang, “Thermally conductive MgO-filled epoxy molding compounds,” IEEE 

Transactions on Components, Packaging and Manufacturing Technology 3(12), 1994–2005 

(2013). 

2. A. Wereszczak, “Hybrid-Filled Epoxy Molding Compositions,” DOE S-Number S124,532, ID Number 201202955, October 2012.
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Surface Microengineering Lowers Friction to Improve Fuel Economy 

Contact: Jun Qu, qujn@ornl.gov, 865-576-9304

Reducing friction on pistons, bearings, and other contacting parts in internal combustion 

engines can substantially increase vehicle fuel efficiency. Studies show that under typical 

operating conditions, friction at the piston ring-cylinder bore is responsible for as much as 

50% of an engine’s total mechanical friction losses; losses in crankshaft bearings and valve 

train components raise the total to more than 70%. Even slight friction reductions in key 

subsystems—multiplied by millions of vehicles on the road—can have a significant impact 

on energy efficiency. 

ORNL researchers are exploring the use of microengineered surfaces to enable engine 

makers to apply new friction-reducing strategies in their designs. Micro-texturing is an

aspect of surface engineering that can control wear debris particles and allow surfaces to 

operate under efficient lubrication. In a collaboration with George Washington University 

(GWU), ORNL investigated micro-geometrically patterned surfaces (textures) and their 

effects on friction reduction. Developments included creating textures on curved surfaces 

like those of engine parts. Laboratory-scale friction testing methods were chosen to simulate 

a range of sliding conditions, such as unidirectional motion, reciprocating motion, elevated 

temperature operation, and operation under a time-varying spectrum of bearing loads

similar to those in pistons, cam lobes, and connecting rod bearings. One of the tests used in 

this evaluation is an ASTM standard for engine friction (ASTM G181), development of 

which was led by ORNL. A custom-built, variable load/speed testing rig has generated 

valuable information on the ability of textures to reduce bearing friction.

Historically, coarse spiral grooves were sometimes machined into journal bearing bores to 

help replenish the lubricant and remove harmful wear particles. Newer microscale 

geometric patterns use advanced manufacturing and surface treatment methods to control 

lubricant flow at the microscale; this project builds on such work. Low-viscosity engine oils 

can reduce viscous losses, but they also reduce the ability of engine bearings to form a thick 

fluid film that separates surfaces. Thinner films tend to be less effective in protecting 

surfaces from wear. Surface microengineering is a promising approach to overcoming some 

of the negative aspects of using low-viscosity oils. 

Chemical and mechanical methods are being evaluated to produce functional textures on 

surfaces like convex piston rings and concave engine bearing bores. GWU is using microlithography, and ORNL is using mechanical methods such as indentation arrays and 

compression of hard wire meshes. GWU research has shown that combinations of features 

like circles and ellipses can be more effective than a single shape to decrease lubricated 

friction. Using the shape combination principle, ORNL’s wire compression texturing 

approach produces grooves and oval depressions. Upcoming work will investigate methods 

of preserving the functionality of micro-textured surfaces using thin films and coatings.

Publication 

1. P. J. Blau, Use of Textured Surfaces to Mitigate Sliding Friction and Wear of Lubricated and 

Non-Lubricated Contacts, ORNL/TM-2012/20, Oak Ridge National Laboratory, 2012.
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84 ORNL Sustainable Transportation Program

The surface of a commercial diesel engine piston ring, after 

friction testing, has a mixed pattern of circles and ellipses to 

reduce friction. The gray area is the site of contact with the 

opposing surface.

Topographic image of a bronze surface patterned by compression 

texturing with grooves and valleys.
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ORNL Sustainable Transportation Program 85

Vehicle Systems

Wireless Charging for Electric Vehicles

Contact: John Miller, millerjm@ornl.gov, 865-946-1469

Wireless charging of electric vehicles, wireless power transfer (WPT), has the potential to 

eclipse conductive vehicle charging because of its autonomy, safety, and convenience to the 

customer. The use of private, secure, standardized radio communication, especially vehicleto-infrastructure, means any vehicle can charge at any location. The complete charging process can in effect be totally transparent to the customer. ORNL researchers are working to 

develop a deep understanding of WPT—to identify the challenges and issues through analytical and experimental work so that technology gaps can be addressed. 

Major accomplishments during FY 2013 included these:

• Achieved >10 kW power transfer at >85% utility input to WPT dc output (battery input) 

using laboratory bench demonstration hardware and software.

• Demonstrated an active front end for ORNL’s WPT base station that uses commercial 

wide bandgap silicon carbide metal oxide semiconductor field effect transistors as the 

grid-input power factor corrector (PFC) stage.

• Developed and demonstrated a high-frequency (HF) power transformer for isolation of 

WPT base station electronics from HF feed cable and primary pad.

• Accessed the controller area network (CAN) in a Prius Hymotion plug-in hybrid test 

vehicle to demonstrate that battery management system messages needed for power 

flow regulation are available.

• Developed primary-side control strategy to manage the PFC voltage used as power 

flow regulation and HF power inverter frequency control to track variations in vehicle 

to ground pad gap.

• Demonstrated DOT standard dedicated short-range communications radio in the feedback loop.

• Developed and delivered all WPT schematics and bill of materials to a commercialization partner.

Other significant findings include assessment of WPT versus the four center-frequency 

bands available, showing that operation in the 20 kHz band is preferable for efficiency and 

misalignment tolerance. ORNL shared testing results for WPT operation in the four frequency band allocations for automotive wireless charging with the SAE J2954 wireless 

charging task force and frequency selection subcommittee. It was also found that a fully 

functional WPT installation will consist of a cascade of five major functional subsystems to 

provide grid power quality, electrical isolation, and low harmonic frequency generation. 

Technology innovations also occurred during year one of this program. Specifically, we incorporated wide bandgap semiconductor devices operating at HF in the WPT PFC stage,

and low-loss soft ferrites in magnetic components. One innovative material yet to be evaluated is a nanocomposite ferrite developed by Ageis Technologies that shows promise of
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86 ORNL Sustainable Transportation Program

Wireless charging: utility pole to vehicle battery.

dramatic bulk and mass reduction of magnetic components. Areas of application for nanocomposite ferrites include the PFC stage input inductors, the HF isolation transformer, and 

the coupler flux guides. The flux guides in particular tend to be thin and long, making them 

susceptible to fracturing under flexure. ORNL’s material scientists devised a coating process 

and material that significantly increases their flexure strength.

Publications, Presentations, and Patent

1. O. C. Onar, J. M. Miller, M. S. Chinthavali, L. Tang, and S. Campbell, “SiC MOSFET 

based single phase active boost rectifier with power factor correction for wireless power 

transfer applications,” presented at IEEE Applied Power Electronics Conference, 

APEC2014, Fort Worth, Texas, March 16–20, 2014. 

2. M. S. Chinthavali, J. M. Miller, and O. C. Onar, “A comprehensive analytical and circuit 

level model development for wireless power transfer systems,” presented at IEEE Applied Power Electronics Conference, APEC2014, Fort Worth, Texas, March 16–20, 2014. 

3. J. M. Miller, O. C. Onar. And P. T. Jones, “ORNL developments in stationary and 

dynamic wireless charging,” presented at Special Session: Advances in Wireless Power 

for Electric Vehicles, IEEE 5th Energy Conversion Congress & Exposition, ECCE2013, 

Denver, September 16–20, 2013.

4. O. C. Onar, J. M. Miller, S. L. Campbell, C. Coomer, C. P. White, and L. E. Seiber, “A 

novel wireless power transfer for in-motion EV/PHEV charging,” presented at IEEE 

Applied Power Electronics Conference, APEC2013, Long Beach, Calif., March 17–21, 

2013.

5. O. Onar and J. M. Miller, “Buffering Energy Storage Systems for Reduced Grid and Vehicle Battery Stress for Wireless In-motion Wireless Power Transfer Systems,” DOE SNumber S-124,533, ID Number 201202956, October 2012.
2013 Annual Report Vehicle Technologies R&D Highlights

ORNL Sustainable Transportation Program 87

Vehicle Systems Integration Laboratory Advances Powertrain Research

Contact: David Smith, smithde@ornl.gov, 865-946-1324

Growing transportation costs and upcoming regulations have increased the focus on vehicle 

fuel efficiency and emissions control, highlighting a need for more aggressive research addressing the complex interactions of advanced powertrain technologies. ORNL’s Vehicle 

Systems Integration (VSI) Laboratory is accelerating the pace of powertrain development by 

performing prototype research and characterization of advanced systems within a controlled environment, while exposing the systems to real-world conditions. VSI Lab capabilities range from advanced light-duty vehicles to hybridized Class 8 powertrains. 

The ability to test a complete “power pack,” consisting of an engine plus a transmission, for 

a fully loaded Class 8 truck is the focus of the VSI Lab. The test cell can handle both conventional and hybrid powertrains for a variety of architectures. The battery emulation system 

provides a flexible environment for subjecting the powertrain under test to a variety of possible energy storage solutions.

To exercise the system and demonstrate performance, a dual dyno configuration was used 

to characterize the maximum torque curve for a conventional powertrain. The maximum 

torque generated by this powertrain was found to be just over 18,000 N∙m, demonstrating 

the full range capability of the VSI powertrain test cell. 

More tests were conducted on the conventional powertrain coupled to the twin dynamometer configuration to evaluate the hardware-in-the-loop and virtual vehicle capabilities. The 

GEM model from the Environmental Protection Agency was incorporated into the system to 

demonstrate the flexibility to integrate a variety of vehicle models. The powertrain test cell 

monitors and records a wide variety of data and can accommodate more sensors as future 

tests dictate.

VSI Powertrain Test Cell “power pack” test configuration 

for heavy duty applications.
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88 ORNL Sustainable Transportation Program

Major equipment upgrades in 2013:

• The AVL Powertrain Dynamometer Test System was procured and installed. Full functionality was demonstrated using a conventional Class 8 heavy duty powertrain consisting of a Cummins ISX.

• The AVL eStorage System (battery emulator) was procured and installed in the powertrain test cell.

• The hardware-in-the-loop system was procured, installed, and commissioned for both 

engine-in-the-loop and powertrain-in-the-loop configurations. Both conventional and 

hybrid powertrain architectures were successfully demonstrated.

• Two complete sets of emissions analyzers were procured, installed, and commissioned 

to measure raw, engine-out emissions and post-aftertreatment (tail-pipe) emissions.

• An AVL 250 kW high-speed (12,000 rpm) dynamometer was ordered for the component 

test cell. It features a through shaft to support two separate experimental setups in the 

laboratory.

• A modular, cross-hatch designed bed plate was ordered for the component test cell to 

provide adequate space to support two experimental setups simultaneously.