NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Overview of Computer-Aided

Engineering of Batteries and

Introduction to Multi-Scale, MultiDimensional Modeling of Li-Ion Batteries

P.I. - Ahmad A. Pesaran,

G.-H. Kim, K. Smith, 

S. Santhanagopalan, K.-J. Lee

National Renewable Energy Laboratory

May 15, 2012

NREL/PR-5400-54425 Project ID #ES117

This presentation does not contain any proprietary, confidential, or otherwise restricted information.

Vehicle Technologies Program (VTP)

Annual Merit Review (AMR)

May 14-18 2012

Washington, DC
2

Overview

Project Start Date: April 2010

Project End Date: September 2014

Percent Complete: 30%

• Cost and life

• Performance and safety

• Lack of validated computer- aided 

engineering tools for accelerating 

battery development cycle 

Total Project Funding:

DOE Share: $9 M

Contractor Share: $7 M

Funding Received in FY11: 

$3.5 M ($2.5 M for subcontracts)

Funding for FY12: 

 $1.0 M expected

Timeline

Budget

Barriers

• Project lead: NREL

• Oak Ridge National Laboratory (ORNL), 

Idaho National Laboratory (INL), 

Colorado School of Mines (CSM)

• EC Power/Penn State Univ (PSU)/ 

Ford/Johnson Controls, Inc. (JCI)

• General Motors (GM)/ANSYS/ESim

• CD-adapco/Battery 

Design/JCI/A123Systems

Partners

Funding provided by Dave Howell of the DOE Vehicle Technologies Program.

The activity is managed by Brian Cunningham of Vehicle Technologies.

This presentation covers two related topics: Overview of the CAEBAT Project and 

NREL’s battery Multi-Scale Multi-Dimensional (MSMD) modeling work under CAEBAT
3

Computer Aided Engineering for 

Electric Drive Vehicle Batteries (CAEBAT)

• Simulation and computer-aided engineering (CAE) tools are widely used to 

speed up the research and development cycle and reduce the number of 

build-and-break steps, particularly in the automotive industry.

• There has been a need to have several user-friendly, 3D, fully integrated, and 

validated CAE software tools for the battery community. 

• National laboratories, industry, and universities have been developing 

models on cost, life, performance (electro-thermal, electrochemical) and 

abuse to simulate lithium-ion batteries.

• Realizing the need, DOE’s Vehicle Technologies Program initiated a project in 

April 2010 to bring together these battery models to develop CAEBAT tools 

for designing batteries.

Battery Pack 

Level Models

Performance

Electrochemical & 

Material Stress Material Stress

Current & Heat 

Transport

Electrode

Level Models

Cell

Level Models

Material

Level Models

Fluid Dynamics

First Principles

Power Demand

 

Source: VARTA

 

Battery Pack 

Design Software

Relevance
4

Objectives

• The overall objective of the CAEBAT project is to incorporate 

existing and new models into “validated” battery design 

suites/tools.

• Objectives of the past year (March 2011 to March 2012) were to:

– Complete negotiations and enter into subcontract agreements with 

the three teams competitively selected in 2010.

– Subcontractors to start technical work.

– NREL to have kickoff and quarterly meetings with subcontractors to 

monitor their technical performance and progress.

– Continue developing NREL’s multi-physics electrochemical lithiumion battery (MSMD) model and document the approach and results 

in a peer-reviewed journal.
5

Relevance

• CAEBAT objectives are relevant to the Vehicle 

Technologies Program’s targets of:

– Plug-in hybrid electric vehicle (PHEV) battery costs of 

$300/kWh and life of 15 years by 2014

– PHEV battery costs of $270/kWh and life of 10+ years by 

2017

– Electric vehicle battery costs of $150/kWh and life of 10 

years by 2020

• The impact of this project when CAEBAT tools are 

made available could be significant:

– Shorten design cycles and optimization of batteries 

– Simultaneously address the barriers of cost, performance, 

life, and safety of lithium-ion with quantitative tools
6

Milestones

Date Milestone or Go/No-Go Decision Status

June 2011 Negotiate and place subcontracts with 

CAEBAT RFP awardees 

Completed

July 2011 Progress review on the work for the CAEBATNREL programCompleted

September 2011 Document NREL’s MSMD modeling approach 

in a peer-reviewed journal

Completed 

July 2012 Document latest NREL battery models, 

solution methods, and codes developed 

under CAEBAT

On Track

September 2012 Technical review of the three CAEBAT 

subcontracts

On Track
7

Overall CAEBAT Strategy

• NREL to coordinate the CAEBAT project activities for DOE

• Perform battery modeling development and use (existing or new) models at national laboratories

• Coordinate and exchange with other organizations doing fundamental materials modeling (such as BATT, Applied 

Battery Research (ABR), or Basic Energy Sciences)

• Collaborate with industry and/or universities through competitive solicitations

• ORNL to develop an interface platform for interactions among all models

CAEBAT

Overall Program

Element 4

Open Architecture

Software

(New Activity)

Element 3

Battery Pack 

Level Models

(Continued Activity)

Element 1

Electrode/Component

Level Models

(Continued Activity)

Element 2

Cell

Level Models

(Continued Activity)

Material-Level Models

Developed under Other 

DOE BATT & ABR 

Programs

Industry/University Subcontracts for 

Development and Use of Design Tools

Approach
8

CAEBAT and MSMD Approach

• Develop CAEBAT software tools with industry 

– Background from FY 10 and Fall of FY11

o We initiated a competitive process (RFP) to solicit cost-shared 

proposals from the industry

o After a comprehensive process, three teams were selected to 

develop CAEBAT software tools

– Approach in 2011

o Completed negotiations and entered into subcontract agreements 

with the three selected teams

o Initiated CAEBAT projects and monitor technical performance and 

progress

o Collaborated with ORNL on Open Architecture Software

• Perform in-house R&D to enhance and further develop NREL’s 

existing electrochemical-thermal (MSMD) models for use by 

CAEBAT participants
9

• NREL negotiated the terms and conditions with the three teams and 

their lower tiers, along with milestones and final budgets, assigned 

separate NREL technical monitors, and then signed the three 

subcontracts.

• Cost sharing by each of the subcontractors is 50%.

• Details: Subcontractor (partners), start date, total project budget, 

DOE/NREL funded amount, NREL tech monitors:

CAEBAT Subcontracts Finalized 

Accomplishments

Team

Subcontract 

Signed

Project 

Budget

NREL Subcontract 

Budget

NREL Technical 

Monitor

EC Power 

(with PSU, JCI, and Ford 

Motor Company)

May 2, 2011 $3.0M $1.50 Shriram 

Santhanagopalan

General Motors 

(with ANSYS and ESim)

June 1, 2011 $7.15M $3.58M Gi-Heon Kim

CD-adapco

(with Battery Design LLC, 

JCI and A123 Systems)

July 1, 2011 $2.73M $1.37M Kandler Smith
10

CAEBAT Projects Underway

• Kickoff meetings were conducted in June 2011 to review plans by each team.

• Weekly, biweekly, or monthly meetings were held to review progress and address issues.

• Quarterly progress review meetings were held at NREL, DOE, and subcontractor sites.

• Each subcontractor presented progress overview at US Drive Technical Committee Meeting.

Each subcontractor 

will provide 

objectives, 

approach, and 

accomplishments of 

their project in the 

next three 

presentations.

ESim

Accomplishments

Tracking projects by 

monthly conference 

calls and face-face 

meetings with the 

three competitive 

teams separately.
11

Coordinating on Open Architecture Software 

• Interacted with ORNL on the 

Open Architecture Software 

element of CAEBAT “that 

facilitates integrating battery 

modeling components within an 

open architecture.”

– Participated in regular 

conference calls

– Participated at ORNL’s kickoff 

meeting

– Provided MSMD model for 

testing the integration approach

– Provided suggestions for 

standardized input data and 

battery state

from ORNL presentation by S. Pannala, 2012 AMR

ORNL will provide the objectives, approach, 

and accomplishments of this project in AMR 

2012 presentation ES121

Accomplishments
12

NREL Battery Modeling Under CAEBAT

Paper published in Journal of the Electrochemical Society

entitled “Multi-Domain Modeling of Lithium-Ion Batteries 

Encompassing Multi-Physics in Varied Length Scales,” 

describing approach and results of NREL MSMD model

Volume 158, Issue 8, pp. A955-A969 (17 June 2011)
13

Commonly Used Porous Electrode Model 

Charge Conservation

η = (φs −φe )−U

(k T ) q

t

T

c p = ∇⋅ ∇ + ′′′ ∂

∂

ρ

• Pioneered by John Newman’s group at the 

University of Berkeley (Doyle, Fuller, and Newman 

1993)

• Captures lithium diffusion dynamics and charge 

transfer kinetics 

• Predicts current/voltage response of a battery

• Provides design guide for thermodynamics, kinetics, 

and transport across electrodes

e e

eff

e e D

eff

s s

eff

s e

Li c

T

U

q j φ φ U T  +σ ∇φ ⋅∇φ +κ ∇φ ⋅∇φ +κ ∇ ⋅∇φ 

 





∂

∂ ′′′ = − − + ln

Charge Transfer Kinetics at Reaction Sites

Species Conservation

Energy Conservation

• Difficult to apply in large-format batteries where 

heat and electron current transport critically affect 

the battery responses

r

Background
14

Published NREL’s MSMD Model Framework

• Introduces multiple computational domains 

for corresponding length-scale physics 

• Decouples LIB geometries into separate 

computation domains

• Couples physics using the predefined inter- domain information exchange

• Selectively resolves higher spatial 

resolution for smaller characteristic length- scale physics

• Achieves high computational efficiency

• Provides flexible & expandable modularized 

framework

Kim et al., “Multi-Domain Modeling of Lithium-Ion Batteries 

Encompassing Multi-Physics in Varied Length Scales,” J. 

Electrochem. Soc., 2011, Vol. 158, No. 8, pp. A955–A969

Through the multi-year effort supported by DOE, NREL has developed a modeling framework for 

predictive computer simulation of lithium-ion batteries (LIBs) known as the Multi-Scale MultiDimensional (MSMD) model that addresses the interplay among the physics in varied scales.

Accomplishments
15

MSMD Segregates Time & Length Scales

• Self-balancing nature allows a continuum approach with 

thermodynamic representation for sub-domain systems

• Time-scale differences in kinetic/dynamic transport 

processes conducive to segregation into sub-domain 

systems

σcc

σce

Electronic conductivity is much 

higher in metal current 

collectors than in a composite 

electrode matrix 

e.g., σce<<σcc

Ds

De

Lithium transport is much 

faster in liquid electrolyte 

than in solid particles

e.g., Ds<<De

Kim et al., “Multi-Domain Modeling of Lithium-Ion 

Batteries Encompassing Multi-Physics in Varied Length 

Scales,” J. Electrochem. Soc., 2011, Vol. 158, No. 8, pp. 

A955–A969

Accomplishments
16

MSMD Decouples Geometry

Domain Invariant

Domain Average

Local information 

transfers from cell to 

electrode sandwich and 

to particles 

Averaged parameters 

transfer back from 

particles to electrode 

sandwich and to the cell

Accomplishments
17

MSMD Decouples Geometry

Domain Invariant

Domain Invariant

Domain Average

Domain Average

Local information 

transfers from cell to 

electrode sandwich and 

to particles 

Averaged parameters 

transfer back from 

particles to electrode 

sandwich and to the cell

Accomplishments
 NATIONAL RENEWABLE ENERGY LABORATORY 18

MSMD Framework is Modularized

Electrode Domain Submodel Development 

Solution Models & Method/Algorithms 

Particle Domain Submodel Development 

Solution Models & Method/Algorithms

Cell Domain Submodel Development 

Solution Models & Method/Algorithms 

Modularized hierarchical architecture of the MSMD model allows independent 

development of submodels for physics captured in each domain

The modularized framework facilitates collaboration with experts across organizations.

1D Spherical particle model Finite Element 

1D porous electrode model Reduced Order 

Approximation

Finite Volume –

Linear superposition

3D Single potential pair 

continuum model

Accomplishments

Examples

Examples

Examples
 NATIONAL RENEWABLE ENERGY LABORATORY 19

MSMD Framework is Modularized

Electrode Domain Submodel Development 

Solution Models & Method/Algorithms 

Particle Domain Submodel Development 

Solution Models & Method/Algorithms

Cell Domain Submodel Development 

Solution Models & Method/Algorithms 

Modularized hierarchical architecture of the MSMD model allows independent 

development of submodels for physics captured in each domain

The modularized framework facilitates collaboration with experts across organizations.

1D Spherical particle model Finite Element 

1D porous electrode model Reduced Order 

Approximation

Finite Volume –

Linear superposition

2D cylindrical particle model Reduced 

Order Method

3D Single potential pair 

continuum model

Finite Element 

Method

Finite Volume 

Method

3D wound potential pair 

continuum (WPPC) model

Accomplishments

Examples

Examples

Examples
20

Application of MSMD for Predicting Cell Behavior 

Large Stacked Prismatic Cell 

• SVM

(state variable method)

• FV-LSM

finite volume – linear 

superposition methods

• SVM

• 1D spherical particle model

Submodel in the Particle Domain 

Submodel in the Electrode Domain 

Submodel in the Cell Domain 

Submodel Choice Solution Method

• 1D porous electrode model

• 3D single potential-pair 

continuum model (SPPC)

Accomplishments
21

Predicted Non-Uniform Utilization in Prismatic Cells

Mid-size sedan PHEV10 US06

Kim et al., “Multi-Domain Modeling of Lithium-Ion Batteries Encompassing Multi-Physics 

in Varied Length Scales,” J. Electrochem. Soc., 2011, Vol. 158, No. 8, pp. A955–A969

Tab size

Accomplishments
22

Application of MSMD for Predicting Cell Behavior 

Wound Prismatic Cell

• SVM

• FVM

(finite volume methods)

• SVM

• 1D spherical particle model

Submodel in the Particle Domain 

Submodel in the Electrode Domain 

Submodel in the Cell Domain 

Submodel Choice Solution Method

• 1D porous electrode model

• 3D Wound Potential-Pair 

Continuum Model (WPPC)

Accomplishments

Spirally wound prismatic cell
23

Response of a Wound Prismatic Cell 

Model results after 500 sec at 4C discharge of 20-Ah cell with 

continuous tabs at surface (left images) and unrolled jelly roll (right 

images)

The simulation shows that non-uniform charge transfer current density 

and temperature are distributed around the bent radius

Accomplishments

Time is 500sec, Temp oC

0.5 1 1.5 2 2.5

0

0.15

33

33.2

33.4

33.6

33.8

Time is 500sec, IpA

0.5 1 1.5 2 2.5

0

0.15

94.5

94.6

94.7

Temperature distribution

Reaction current density distribution 
24

Thermal Response of Wound Cylindrical Cells 

Temperature imbalance at 4C discharge

Continuous-tabs (CT) cell

Impact of electrical current transport design:

• With higher number of tabs, current and 

temperature distribution are more uniform

Accomplishments

K.-J. Lee, K. Smith, G.-H. Kim, “A Three-Dimensional Thermal-Electrochemical Coupled Model for Spirally Wound Large-Format Lithium-Ion 

Batteries,” presented at Space Power Workshop; Los Angeles, CA; April 18, 2011.
25

Collaboration and Coordination

ESim

• Coordination with other national labs under CAEBAT

– ORNL (open architecture software)

– INL (providing electrolyte properties to CD-adapco)

• Collaboration with CAEBAT subcontractors to develop 

battery CAE design tools

– General Motors, ANSYS, ESim

– CD-adapco, Battery Design, A123 Systems, and JCI

– EC Power, Penn State U, JCI, and Ford 

• Colorado School of Mines – Published a joint paper on 

integrated general chemistry solver for charge transfer and 

side reactions in Li-ion
26

Proposed Future Work

• Collaborate with CAEBAT partners to develop CAEBAT tools

• Continue enhancing MSMD modeling framework 

• Conduct experiments to validate NREL’s MSMD models

• Work with others in using MSMD models

• Collaborate with ORNL on implementing Open Architecture 

Software

• Review subcontractors’ plans with focus on validation of cell 

and pack models

• Key upcoming milestones:

– Document latest NREL battery model developments by publishing 

journal papers

– Compete technical review of the three CAEBAT subcontracts

– Review 1st version of CAEBAT subcontractors’ tools for cells

• Work with collaborators and partners to promote the use of 

CAEBAT tools within the battery community
27

Publications and Presentations

• K.-J. Lee, K. Smith, G.-H. Kim, “A Three-Dimensional ThermalElectrochemical Coupled Model for Spirally Wound Large-Format LithiumIon Batteries,” presented at Space Power Workshop; Los Angeles, CA; April 

18, 2011.

• A.M. Colclasure, K.A. Smith, R.J. Kee, “Modeling Detailed Chemistry and 

Transport for Solid Electrolyte Interface (SEI) Films in Li-ion Batteries,” 

Electrochimica Acta. Vol. 58, 30 December 2011; pp. 33-43.

• G.-H. Kim, K. Smith, K.-J. Lee, S. Santhanagopalan, A. A. Pesaran, “MultiDomain Modeling of Lithium-Ion Batteries Encompassing Multi-Physics in 

Varied Length Scales,” J. Electrochem. Soc., 2011, Vol. 158, No. 8, pp. A955–

A969.

• A. A. Pesaran, G.-H. Kim, K. Smith, K.-J. Lee, and S. Santhanagopalan, 

“Computer-Aided Engineering of Batteries for Designing Better Li-Ion 

Batteries,” presented at the Advanced Automotive Battery Conference, 

Orlando, Florida; February 6-8, 2012.
28

Summary

• CAEBAT activity was initiated to develop battery computer-aided 

engineering tools to accelerate development of batteries for electric 

vehicles.

• CAEBAT activities at NREL consist of two parallel paths:

o Working with industry to develop CAEBAT tools through cost-shared 

subcontracts

o NREL in-house electrochemical battery model development

• After a competitive process, NREL executed three subcontracts with 

three industry teams – a total of $14M with 50% cost share from 

industry – to develop the battery computer tools.

o GM/ANSYS/Esim

o CD-adapco/Battery Design/A123 Systems/JCI

o EC Power/Pennsylvania State University/JCI/Ford

• NREL collaborated with ORNL on CAEBAT open architecture software.

• NREL continued the development of its MSMD electrochemical/thermal 

modeling and published papers (for stacked prismatic, wound cylindrical, 

and wound prismatic configurations).

• CAEBAT project is proceeding very well and according to plan.
Technical Back-Up Slides
30

Cell Domain Models

• SPPC (Single Potential-Pair Continuum) model: 

applicable to stack prismatic cells, tab-less wound 

cylindrical/(prismatic) cells:

• MPPC (Multi Potential-Pair Continuum) model: 

applicable to

alternating stacked

prismatic cells:

• WPPC (Wound Potential-Pair Continuum) model: 

applicable to spirally

wound cylindrical/

(prismatic) cells:

• Lumped model: applicable to small cells

NREL’s Cell-Domain Models: Orthotropic Continuum Model

√

√

Discussed in this presentation

Wound cell with continuous tab
31

Electric Current Transport – Prismatic 

4C discharge / Single-side cooling
32

Electric Current Transport – Prismatic 

4C discharge / Single-side cooling
33

Electric Current Transport – Prismatic 

0 110 135 215

-100

-80

-60

-40

-20

0

φe [mV]

x [μm]

1C

2C

3C

4C

4C discharge / Single-side cooling
34

Electric Current Transport – Prismatic 

0 110 135 215

-100

-80

-60

-40

-20

0

φe [mV]

x [μm]

1C

2C

3C

4C

4C discharge / Single-side cooling cooled top bottom
35

Wound Cells (Cylindrical or Prismatic)

• A pair of wide current collectors

• Two electrode pairs

• Cylindrical or prismatic cells

Stacking : Forming the first pair between inner electrodes 

Winding : Forming the second pair between outer electrodes

Current collector

Current collector

Separator

electrode

electrode

Pairing Inner 

Electrodes

Separator

electrode

electrode

Pairing Outer 

Electrodes

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0

0.05

0.1

X [m]

] m[ Y

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0

0.05

0.1

X [m]

] m[ Y

Negative current collector

Positive current collector

Inner electrode pair

Outer electrode pair
36

WPPC (Wound Potential-Pair Continuum)

Separator Separator

Unit stratum/

finite cell volume

Applicable to flat 

wound prismatic cells
37

Kinetics Response – Wound Cylindrical Cell

Impact of electrical current transport design

Continuous-tabs (CT) cell

Accomplishments

K.-J. Lee, K. Smith, G.-H. Kim, “A Three-Dimensional Thermal-Electrochemical Coupled Model for Spirally Wound Large-Format Lithium-Ion 

Batteries,” presented at Space Power Workshop; Los Angeles, CA; April 18, 2011.