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.

Choices and Requirements of Batteries 

for EVs, HEVs, PHEVs

A CALSTART Webinar

Ahmad A. Pesaran

National Renewable Energy 

Laboratory

April 21, 2011

NREL/PR-5400-51474
NATIONAL RENEWABLE ENERGY LABORATORY

Introduction to NREL

Introduction to Electric Drive Vehicles (EDVs) 

Battery Technologies for Hybrid Electric Vehicles (HEVs), 

Plug-in Hybrid Electric Vehicles (PHEVs) & Electric 

Vehicles (EVs)

Battery Requirements for EDVs

Concluding Remarks

2

Outline of the Presentation
NATIONAL RENEWABLE ENERGY LABORATORY 3

U.S. Department of Energy National Labs

Los Alamos 

National 

Laboratory

Lawrence 

Livermore 

National 

Laboratory

Sandia 

National 

Laboratories

Lawrence 

Berkeley 

National 

Laboratory

Idaho

National 

Laboratory

Pacific Northwest 

National 

Laboratory

Argonne 

National 

Laboratory

Brookhaven 

National 

Laboratory

National 

Energy 

Technology 

Laboratory

Savannah 

River National 

Laboratory

Oak Ridge 

National 

Laboratory

Science

Fossil Energy

Nuclear Energy

Nuclear Security

Energy Efficiency and 

Renewable Energy

NREL is the only DOE national laboratory dedicated to 

renewable and energy-efficient technologies

NREL is operated for DOE by the Alliance for Sustainable Energy

(Midwest Research Institute and Battelle) 
NATIONAL RENEWABLE ENERGY LABORATORY

NREL’s Portfolio on 

Energy Efficiency and Renewable Energy

4

• Renewable Electricity 

• Electric Systems Integration

• Net-Zero Energy Buildings

Electricity

• Renewable Fuels

• Efficient and Flexible 

Vehicles

Fuels

Underpinned with Science

Photoconversion Computational Science Systems Biology From Concept to Consumer

Solar

Wind & 

Water

Geothermal

Buildings

Electricity

Biomass

Transportation

Hydrogen & 

Ocean Fuel Cells

International Programs Strategic Analysis Integrated Programs
NATIONAL RENEWABLE ENERGY LABORATORY 5

Center for Transportation Technologies and Systems 

Testing & 

Analysis

Systems 

Analysis

Fleet Test & 

Evaluation

ReFUEL Lab

Electric Vehicle 

Grid Integration

Tires

CoolCAB

Performance 

Fuels

Health Impacts

Advanced 

PetroleumBased Fuels

NonPetroleum 

Based Fuels

Advanced 

Vehicles

Advanced Power 

Electronics

Energy Storage

Vehicle 

Ancillary Loads 

Reduction

Emphasis on light-, medium-, and heavy-duty vehicles

Supporting DOE’s Vehicle Technologies Office and its FreedomCAR and 

Fuel Partnership and 21st Century Truck Partnership
NATIONAL RENEWABLE ENERGY LABORATORY

NREL Energy Storage Projects

6

Energy Storage Task

Materials 

Development

Components 

Modeling

Components 

Testing Life Studies System Evaluation

Supporting DOE and helping industry to achieve energy storage targets for electrified vehicles 

Current Density

Temperature

Images courtesy of NREL Energy Storage team
NATIONAL RENEWABLE ENERGY LABORATORY

Introduction to NREL

Introduction to Electric Drive Vehicles (EDVs)

Battery Technologies for HEVs, PHEVs & EVs

Battery Requirements for EDVs

Concluding Remarks

7

Outline of the Presentation
NATIONAL RENEWABLE ENERGY LABORATORY 8

Spectrum of EDV Technologies

Size of Electric Motor (and associated energy storage system)

Size of Combustion Engine

Conventional internal combustion engine (ICE) Vehicles

Micro hybrids (start/stop)

Mild hybrids (start/stop + kinetic energy recovery)

Full hybrids (medium hybrid capabilities + 

electric launch)

Plug-in hybrids (full hybrid capabilities 

+ electric range)

Electric Vehicles (battery or fuel cell)

Medium hybrids (mild hybrid + engine assist)

Axes not to scale
NATIONAL RENEWABLE ENERGY LABORATORY 9

Hybrid Electric Vehicle Configurations
NATIONAL RENEWABLE ENERGY LABORATORY 10

Plug-In Vehicle Configurations
NATIONAL RENEWABLE ENERGY LABORATORY

Micro 

hybrids

Mild

hybrids

Full

hybrids 

Plug-in 

hybrids 

Electric 

Honda FCX

+ Electric Range

or Launch

Saturn Vue

Medium 

hybrids 

Adapted and modified from “From Stop-Start to EV “ by Derek de Bono presented at 

the SAE Hybrid Vehicle Technologies Symposium , San Diego, CA, February 2010

CITROËN C3 

BMW ED

Chevy Tahoe

Chevy Malibu

11

Examples of Light-Duty EDVs in the Market
NATIONAL RENEWABLE ENERGY LABORATORY

Battery is the Critical Technology for EDVs

12

 Enables hybridization and electrification 

 Provides power to motor for acceleration

 Provides energy for electric range and other auxiliaries

 Helps downsizing or eliminating the engine

 Stores kinetic and braking energy 

Adds cost, weight, and volume

Decreases reliability and durability

× Decreases performance with aging

× Raises safety concerns 

Lithium-ion battery cells, module, and battery pack for the Mitsubishi iMiEV

(All images courtesy of Mitsubishi)

Saves fuel

and

reduces 

emissions
NATIONAL RENEWABLE ENERGY LABORATORY

Introduction to NREL

Introduction to HEVs, PHEVs and EVs

Battery Technologies for HEVs, PHEVs & EVs

Battery Requirements for EDVs

Concluding Remarks

13

Outline of the Presentation
NATIONAL RENEWABLE ENERGY LABORATORY

Battery Choices: Energy and Power

14

NiMH proven 

sufficient for 

many HEVs. 

Still recovering 

early factory 

investments.

Lithium ion 

technologies 

can meet most 

of the required 

EDV targets in 

the next 10 

years.

Source: www1.eere.energy.gov/vehiclesandfuels/facts/2010_fotw609.html
NATIONAL RENEWABLE ENERGY LABORATORY

Qualitative Comparison of Major Automotive Battery 

Technologies

Attribute Lead Acid NiMH Li-Ion

Weight (kg)

Volume (L)

Capacity/Energy (kWh)

Discharge Power (kW)

Regen Power (kW)

Cold-Temperature (kWh & kW) 

Shallow Cycle Life (number)

Deep Cycle Life (number)

Calendar Life (years)

Cost ($/kW or $/kWh)

Safety- Abuse Tolerance

Maturity – Technology

Maturity – Manufacturing

15

Key

Poor

Fair

Good
NATIONAL RENEWABLE ENERGY LABORATORY 16

Projections for Automotive Batteries

Source: Hiroshi Mukainakano, AABC Europe 2010
NATIONAL RENEWABLE ENERGY LABORATORY

Challenges & Opportunities with Li-Ion Technologies 

for EDVs

17

• High cost, many chemistries, cell sizes, shapes, module configurations, 

and battery pack systems.

• Integration with proper electrical, mechanical, safety, and thermal 

management is the key.

• New developments and potential advances make it difficult to pick 

winners.

Various sources:

2009 DOE Merit Review

2010 ETDA Conference

2010 SAE HEV Symposium
NATIONAL RENEWABLE ENERGY LABORATORY

Lithium Ion Battery Technology—Many Chemistries

18

Voltage ~3.2-3.8 V

Cycle life ~1000-5000

Wh/kg >150

Wh/l >400

Discharge -30 to 60oC

Shelf life <5%/year

Source: Robert M. Spotnitz, Battery Design LLC, “Advanced EV and HEV Batteries”

Many cathodes are possible

Cobalt oxide

Manganese oxide

Mixed oxides with nickel

Iron phosphate

Vanadium-oxide based

Many anodes are possible

Carbon/Graphite

Titanate (Li4Ti5O12)

Titanium-oxide based

Silicon based

Metal oxides

Many electrolytes are possible

LiPF6 based

LiBF4 based

Various solid electrolytes

Polymer electrolytes

Ionic liquids
NATIONAL RENEWABLE ENERGY LABORATORY 19

Electrochemical Window in Lithium Ion Batteries

Source: Yoon Seok Jung, et. al. Presented 

at 2011 MRS Spring Meeting, San 

Francisco, CA
NATIONAL RENEWABLE ENERGY LABORATORY 20

Characteristics of Cathode Materials

Mixed metal oxide cathodes are replacing cobalt oxide as the dominant chemistry.

Mn2O4 has been around for many years – good for high power; improvements in high 

temperature stability reported recently.

LiFePO4 is now actively pursued by many as the cathode of choice for vehicle applications

- safe on overcharge 

- need electronics to accurately determine state of charge (SOC) 

- may require larger number of cells due to lower cell voltage

Other high voltage phosphates are currently being considered.

Theoretical values for cathode materials relative to graphite anode and LiPF6 electrolyte

*

Source: Robert M. Spotnitz, Battery Design LLC 

Material Δx mAh/g Avg. V Wh/kg Wh/L

LiCoO2 (Cobalt)* 0.55 151 4.00 602 3,073

LiNi0.8Co0.15Al0.05O2 (NCA)* 0.7 195 3.80 742 3,784

LiMn2O4 (Spinel)* 0.8 119 4.05 480 2,065

LiMn1/3Co1/3Ni1/3O2 (NMC 333)* 0.55 153 3.85 588 2,912

LiMnxCoyNizO2 (NMC non-stoichiometric) 0.7 220 4.0 720 3,600

LiFePO4 (Iron Phosphate)* 0.95 161 3.40 549 1,976
NATIONAL RENEWABLE ENERGY LABORATORY

Johnson Control-Saft

Altair Nanotechnologies

LG Chem

Electrovaya

Dow Kokam

SK Innovation

NEC/Nissan

GS Yuasa

Sony

Sanyo

Samsung

Panasonic

Lishen

Pionics

Other Chinese companies

21

Many Commercial Cathode Oxide-Based Li-Ion Batteries are 

Available

CALSTART Energy Storage Compendium

Conhttp://www.calstart.org/Libraries/Publications/Energy 

_Storage_Compendium_2010.sflb.ashx

Mixed metal oxide cathodes (> 200 mAh/g)
NATIONAL RENEWABLE ENERGY LABORATORY

Lithium Iron Phosphate (LiFePO4) Cathodes 

22

+ High stability and non-toxic

+ Good specific capacity

+ Flat voltage profile

+ Cost effective (less expensive cathode)

+ Improved safety

Issues addressed recently:

– Lower voltage than other cathodes

(Alternate phosphates – manganese, 

vanadium, etc. – are currently being investigated)

– Poor Li diffusion (DLi~ 10-13 cm2/sec)

(Overcome by doping the cathode)

– Poor electronic conductivity (~ 10-8 S/cm)

(Overcome by blending/coating with conductive carbon)

Other approaches used to overcome poor characteristics:

– Use nano LiFePO4–carbon composite

– Use larger number of cells

– Nano-structured materials

Source: Various papers from the 23rd International Battery Seminar & Exhibit, March 13-16, 2006, Ft. Lauderdale, FL.

Source: Online brochures from Valence Technology,

http://www.valence.com/ucharge.asp
NATIONAL RENEWABLE ENERGY LABORATORY 23

Improvements in Phosphate-based Cathodes

Valence Technology 18650 Cells

100 Wh/kg in cell 84 Wh/kg in U Charge module

The battery with standard lead acid battery form factor 

includes a battery management system.

Source: 2006 On line brochures from Valence Technology, 

http://www.valence.com/ucharge.asp

Source: Andrew Chu (A123 Systems) from the 23rd International Battery Seminar & Exhibit, 

March 13-16, 2006, Ft. Lauderdale, FL.

A123 Systems with 

26650 Cells 100 

Wh/kg

Newer 

Phosphates

Voltage vs. 

Li

Iron 3.6 V

Manganese 4.1 V

Cobalt 4.8 V

Nickel 5.1 V

Under R&D

3.2-Ah Real Capacity

15-mOhm
NATIONAL RENEWABLE ENERGY LABORATORY

Improvements on the Anode—Titanate

24

Altair Nanotechnologies Inc.

Improved low temperature 

performance 

80–100 Wh/kg

2,000–4,000 W/kg

Source: E. House (Altair Nanotechnologies) from 

the 23rd International Battery Seminar & Exhibit, 

March 13-16, 2006, Ft. Lauderdale, FL.
NATIONAL RENEWABLE ENERGY LABORATORY

Improvements on the Anode—Silicon

25

25 nm

100 nm 500 nm

1000 nm

Source: Recent (2011) Reports on SiO Carbon Composite Anodes (Shriram Santhanagopalan-NREL)

Advantages:

- Very high theoretical capacity

- No lithium deposition

- High rate capability

- No need for an SEI

Issues at hand:

- High volume expansion

- Low cell voltage

- Poor cyclability
NATIONAL RENEWABLE ENERGY LABORATORY

Improvements to Other Components

26

LG Chem’s Safety 

Dow’s High Temperature Reinforcing Separator (SRS) Electrolytes claimed to be stable 

up to 5 V 

Binders:

- Shift from fluoride-based binders

- SBR and CMC increasingly popular

Conductive Coatings

Separators

Sources: Shriram Santhanagopalan and Anne Dillon (NREL)
NATIONAL RENEWABLE ENERGY LABORATORY

Toyota

Honda

Nissan

Mitsubishi

Isuzu

Mitsubishi Fuso

Hino

Daihatsu

Subaru PEVE

Panasonic

Automotive Energy

Supply

LEJ

Johnson Control-Saft

Cobasys/A123

Hitachi Vehicle Energy

Sanyo

NiMH Makers Car Makers LIB Makers

Ford

Daimler

VW/Audi

PEVE or 

Toyota in- house

Cobasys

NEC/NEC Tokin

Mitsubishi Corp.

GS Yuasa

Toyota System

GM-Daimler

-BMW System

Batt.Supply

Investment

50%

50%

34%

51%

15%

※including plan & assumption Hyundai LG Chemical

60%

40%

Hitachi Maxell

Hitachi

Shin- kobe

63.8%

28.9%

7.3%

Compact Power

GM

Sanyo

Pb

Pb

27

Relationship Between Car Makers and Battery Makers 

Source: Nomura Research Institute, Ltd.
NATIONAL RENEWABLE ENERGY LABORATORY

• Solid/Electrolyte Interphase (SEI) Layer

– Passive protective layer, product of organic electrolyte decomposition

– Mostly formed during first cycle of battery, but continues to grow at 

slow rate

– May penetrate into electrode & separator pores

– High-temperature effects

– Low-temperature effects (during charging)

• Changes of Active Material

– Volume changes during insertion/de-insertion (~10%)

– Solvent intercalation, electrolyte reduction, gas evolution inside LixC6

 Stress  Cracks

• Changes of Composite Electrode

– SEI & volume changes cause: 

• Contact loss between LixC6, conductive binder, and current collector

• Reduced electrode porosity

28

Anode Aging
NATIONAL RENEWABLE ENERGY LABORATORY

4000

50%

70%

Potential

Potential

Potential

Potential

29

Battery Cycle Life Depends on State-of-Charge Swing 

• PHEV battery likely to deep-cycle each day driven: 15 yrs equates to 4,000–5,000 deep cycles

• Also need to consider combination of high- and low-frequency cycling

Source: Christian Rosenkranz (Johnson Controls) at EVS 20, Long Beach, CA, November 15-19, 2003
NATIONAL RENEWABLE ENERGY LABORATORY

0 0.2 0.4 0.6 1

1.05

1.1

1.15

1.2

1.25

1.3

1.35

Time (years)

Relative Resistance

30

40

47.5

55

Source: Bloom and Battaglia, 2008

30

Battery Degrades Faster at Higher Temperatures

Calendar (Storage) Fade

Temperature (°C)

Relative Power
NATIONAL RENEWABLE ENERGY LABORATORY

Capacity decreases and resistance increases by:

• Both high and low SOC charge-discharge 

• High temperatures

• Low temperatures during charging

• Surface chemistry (anode and cathode)

• Phase transitions/structural changes (cathode)

31

Summary of Aging and Degradation
NATIONAL RENEWABLE ENERGY LABORATORY

Thermal Runaway

Leak

Smoke

Gas Venting

If Heating Rate 

Exceeds 

Dissipation Rate

Internal Short Circuit

Lithium Plating

Causing or Energizing 

Internal Events or 

Exothermic Reactions

Decompositions

Electrochemical 

Reactions

Electrode-Electrolyte

Reactions

External Heating

Over-Charging

High Current Charging

Crush

Nail penetration

External 

Abuse Conditions

External Short

Over-Discharging

Rapid Disassembly

Flames

Thermal Runaway

32

Safety—Li-Ion Thermal Runaway 

Flammable electrolyte 
NATIONAL RENEWABLE ENERGY LABORATORY

Introduction to NREL

Introduction to Electric Drive Vehicles (EDVs)

Battery Technologies for HEVs, PHEVs & EVs

Battery Requirements for EDVs

Concluding Remarks

33

Outline of the Presentation
NATIONAL RENEWABLE ENERGY LABORATORY

Vehicle size (weight and shape) 

Electrification/hybridization purpose

• Start/stop

• Assist or launch

• Electric drive

Degree of hybridization

Driving profiles and usage

Auxiliary or accessory electrification

Expected fuel economy

Electric range

Energy storage characteristics (acceptable SOC range)

34

Energy Storage Requirements

Vehicle simulation tools are usually used to estimate power and energy needs. 

Economics and market needs are used to identify life and cost.

(Power, Energy, Cycle Life, Calendar Life and Cost) 
NATIONAL RENEWABLE ENERGY LABORATORY

Energy Needs in Light-Duty Electric-Drive Vehicles

35

NiMH and Li-ion: Yes

Ucap: Likely

Ucap + VRLA: Possible

Micro Hybrids (12V-42V: Start-Stop, 

Launch Assist)

NiMH: No

Li-ion: Yes

Ucaps + high energy Li-ion: Possible 

Plug-in HEV (and EV)

NiMH and Li-ion: Yes 

Ucaps: Likely if fuel cell is not downsized

Ucaps + (NiMH or Li-Ion): Possible

Fuel Cell Hybrids

NiMH and Li-ion: Yes

Ucaps: Possible 

Ucaps + (NiMH or Li-Ion): Possible

Full/Med Hybrids (150V-350V: Power 

Assist HEV)

NiMH and Li-ion: Yes

Ucaps: Likely if engine is not downsized much

Ucaps + VRLA: Possible

Mild/Med Hybrids (42V-150V: Micro 

HEV Function + Regen)

15-25 Wh

25-80 Wh

70-200 Wh

70-200 Wh

Min in use 

energy needed

http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/45596.pdf * Energy for a ultracapacitor in combination with Li-Ion 

EV: 20-40 kWh

Energy Storage Technology

PHEV: 5-15 kWh

(50-90 Wh*)
NATIONAL RENEWABLE ENERGY LABORATORY

Power Needs in Light-Duty Electric-Drive Vehicles

36

NiMH and Li-ion: Yes

Ucap: Likely

Ucap + VRLA: Possible

Micro Hybrids (12V-42V: Start-Stop, 

Launch Assist)

NiMH: No

Li-ion: Yes

Ucaps + high energy Li-ion: Possible 

Plug-in HEV (and EV)

NiMH and Li-ion: Yes 

Ucaps: Likely if Fuel Cell is not downsized

Ucaps + (NiMH or Li-Ion): Possible

Fuel Cell Hybrids

NiMH and Li-ion: Yes

Ucaps: Possible 

Ucaps + (NiMH or Li-Ion): Possible

Full/Med Hybrids (150V-350V: Power 

Assist HEV)

NiMH and Li-ion: Yes

Ucaps: Likely if engine is not downsized much

Ucaps + VRLA: Possible

Mild/Med Hybrids (42V-150V: Micro 

HEV Function + Regen)

3-5 kW

5-15 kW

15-50 kW

15-50 kW

Range of 

Power needed

http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/45596.pdf * Energy for a ultracapacitor in combination with Li-Ion 

EV: 80-120 kW

Energy Storage Technology

PHEV: 20-50 kW

Power/Energy 

use = 200-300

P/E use = 50-200

P/E use = 20-150

P/E use = 20-150

P/E use = 3-8

P/E use = 1.5-4
NATIONAL RENEWABLE ENERGY LABORATORY

Developed jointly by U.S. DOE (with support from national 

labs), automotive OEMs (through USABC), with input from 

battery industry

Requirements and targets are specified to make EDVs 

eventually competitive with conventional ICE vehicles on a 

mass-produced scale

37

USABC/FreedomCAR Battery Requirements
NATIONAL RENEWABLE ENERGY LABORATORY 38

Energy Storage Requirements for Micro Hybrids

(at End of Life)

http://www.uscar.org/guest/article_view.php?articles_id=85
NATIONAL RENEWABLE ENERGY LABORATORY

Discharge Power: 

6 kW for 2s

Available 

Energy: 30 Wh

at 1 kW rate

Cycle Life: 

750,000 (150,00 

miles)

Weight and 

Volume 

Restrictions

Calendar life:

15 years

Mass Produced 

System Price: $80

($13.3/kW)

http://www.uscar.org/guest/article_view.php?articles_id=85

39

Energy Storage Requirements for Micro Hybrids

(at End of Life)
NATIONAL RENEWABLE ENERGY LABORATORY

FreedomCAR 42 V Energy Storage System End-of-Life Performance Goals (August 2002)

42 Volt Targets Rev. August 2002 Start-Stop M-HEV P-HEV

Discharge Pulse Power (kW) 6 2 sec 13 2 sec 18 10 sec

Regenerative Pulse Power (kW) N/A 8 2 sec 18 2 sec

Engine-Off Accessory Load (kW) 3 5 min 3 5 min 3 5 min

Available Energy (Wh @ 3 kW) 250 300 700

Recharge Rate (kW) 2.4 kW 2.6 kW 4.5 kW

Energy Efficiency on Load Profile (%) 90 90 90

Cycle Life, Miles/Profiles (Engine Starts) 150k (450k) 150k (450k) 150k (450k)

Cycle Life and Efficiency Load Profile Zero Power Assist (ZPA) Partial Power Assist (PPA) Full Power Assist (FPA)

Cold Cranking Power @ -30°C (kW) 8 21 V Min. 8 21 V Min. 8 21 V Min.

Calendar Life (Years) 15 15 15

Maximum System Weight (kg) 10 25 35

Maximum System Volume (Liters) 9 20 28

Selling Price ($/system @ 100k/yr) 150 260 360

Maximum Open Circuit Voltage (Vdc) after 1 sec 48 48 48

Minimum Operating Voltage (Vdc) 27 27 27

Self Discharge (Wh/day) <20 <20 <20

Heat Rejection Coefficient (W/°C) N/A N/A >30

Maximum Cell-to-Cell Temperature Difference (°C) N/A N/A <4

Operating Temperature Range (°C) -30 to +52 -30 to +52 -30 to +52

Survival Temperature Range (°C) -46 to +66 -46 to +66 -46 to +66

40

Energy Storage Requirements for

Low-Voltage Mild Hybrids

http://www.uscar.org/guest/article_view.php?articles_id=85
NATIONAL RENEWABLE ENERGY LABORATORY

FreedomCAR 42 V Energy Storage System End-of-Life Performance Goals (August 2002)

42 Volt Targets Rev. August 2002 Start-Stop M-HEV P-HEV

Discharge Pulse Power (kW) 6 2 sec 13 2 sec 18 10 sec

Regenerative Pulse Power (kW) N/A 8 2 sec 18 2 sec

Engine-Off Accessory Load (kW) 3 5 min 3 5 min 3 5 min

Available Energy (Wh @ 3 kW) 250 300 700

Recharge Rate (kW) 2.4 kW 2.6 kW 4.5 kW

Energy Efficiency on Load Profile (%) 90 90 90

Cycle Life, Miles/Profiles (Engine Starts) 150k (450k) 150k (450k) 150k (450k)

Cycle Life and Efficiency Load Profile Zero Power Assist (ZPA) Partial Power Assist (PPA) Full Power Assist (FPA)

Cold Cranking Power @ -30°C (kW) 8 21 V Min. 8 21 V Min. 8 21 V Min.

Calendar Life (Years) 15 15 15

Maximum System Weight (kg) 10 25 35

Maximum System Volume (Liters) 9 20 28

Selling Price ($/system @ 100k/yr) 150 260 360

Maximum Open Circuit Voltage (Vdc) after 1 sec 48 48 48

Minimum Operating Voltage (Vdc) 27 27 27

Self Discharge (Wh/day) <20 <20 <20

Heat Rejection Coefficient (W/°C) N/A N/A >30

Maximum Cell-to-Cell Temperature Difference (°C) N/A N/A <4

Operating Temperature Range (°C) -30 to +52 -30 to +52 -30 to +52

Survival Temperature Range (°C) -46 to +66 -46 to +66 -46 to +66

Energy Storage Requirements for

Low-Voltage Mild Hybrids Discharge 

Power: 13 kW 

for 2s

Available 

Energy: 300 Wh

at 3 kW rate

Cycle Life: 

450,000 

(150,00 miles)

Weight and 

Volume 

Restrictions

Calendar Life at

30°C: 15 years 

Mass Produced 

System Price: 

$260 ($20/kW)

41

http://www.uscar.org/guest/article_view.php?articles_id=85
NATIONAL RENEWABLE ENERGY LABORATORY 42

For Medium or Full Hybrids, and Fuel Cell Vehicles

(at End of Life)

http://www.uscar.org/guest/article_view.php?articles_id=85

FreedomCAR Energy Storage System Performance Goals for Power-Assist Hybrid Electric Vehicles (November 2002)

Characteristics Units Power-Assist (Minimum) Power-Assist (Maximum)

Pulse Discharge Power (10s) kW 25 40

Peak Regenerative Pulse Power (10s) kW 20 (55-Wh pulse) 35 (97-Wh pulse)

Total Available Energy (over DOD range where 

power goals are met) KWh 0.3 (at C1/1 rate) 0.5 (at C1/1 rate)

Minimum Round-trip Energy Efficiency % 90 (25-Wh cycle) 90 (50-Wh cycle)

Cold Cranking Power at -30°C (three 2-s pulses, 

10-s rests between) kW 5 7

Cycle Life for Specified SOC Increments cycles 300,000 25-Wh cycles (7.5 

MWh)

300,000 50-Wh cycles (15 

MWh)

Calendar Life years 15 15

Maximum Weight kg 40 60

Maximum Volume l 32 45

Operating Voltage Limits Vdc max ≤ 400,

min ≥ (0.55 x Vmax)

max < 400,

min > (0.55 x Vmax)

Maximum Allowable Self-discharge Rate Wh/day 50 50

Temperature Range:

Equipment Operation

Equipment Survival

°C -30 to +52

-46 to +66

-30 to +52

-46 to +66

Production Price @ 1,000,000 units/year $ 500 800
NATIONAL RENEWABLE ENERGY LABORATORY

FreedomCAR Energy Storage System Performance Goals for Power-Assist Hybrid Electric Vehicles (November 2002)

Characteristics Units Power-Assist (Minimum) Power-Assist (Maximum)

Pulse Discharge Power (10s) kW 25 40

Peak Regenerative Pulse Power (10s) kW 20 (55-Wh pulse) 35 (97-Wh pulse)

Total Available Energy (over DOD range where 

power goals are met) KWh 0.3 (at C1/1 rate) 0.5 (at C1/1 rate)

Minimum Round-trip Energy Efficiency % 90 (25-Wh cycle) 90 (50-Wh cycle)

Cold Cranking Power at -30°C (three 2-s pulses, 

10-s rests between) kW 5 7

Cycle Life for Specified SOC Increments cycles 300,000 25-Wh cycles (7.5 

MWh)

300,000 50-Wh cycles (15 

MWh)

Calendar Life years 15 15

Maximum Weight kg 40 60

Maximum Volume l 32 45

Operating Voltage Limits Vdc max ≤ 400,

min ≥ (0.55 x Vmax)

max < 400,

min > (0.55 x Vmax)

Maximum Allowable Self-discharge Rate Wh/day 50 50

Temperature Range:

Equipment Operation

Equipment Survival

°C -30 to +52

-46 to +66

-30 to +52

-46 to +66

Production Price @ 1,000,000 units/year $ 500 800

http://www.uscar.org/guest/article_view.php?articles_id=85

For Medium or Full Hybrids, and Fuel Cell Vehicles

(at End of Life)

43

Available Energy = 300 

Wh at C1/1 rate 

Calendar Life at 30°C = 15 years

Cycle Life (charge sustaining) = 

300,000 cycles (150,000 miles) 

Peak Power Discharge 

(10s) = 25 kW 

Cost for Mass Produced System = 

$500 ($20/kW)
NATIONAL RENEWABLE ENERGY LABORATORY 44

http://www.uscar.org/guest/article_view.php?articles_id=85
NATIONAL RENEWABLE ENERGY LABORATORY 45

Available Energy = 11.6 kWh (ΔSOC = 70%)

Capacity (EOL) = 16.6 kWh 

Calendar Life at 35°C = 15 years

Cost for Mass Produced System = $3,400

($300/kWh available energy)

Cycle Life (charge depleting) 

= 5,000 cycles

Peak Power Discharge (10S) = 38 kW 

C-rate ~ 10–15 kW

Cycle Life (charge sustaining) =200K–300K cycles

40 Mile EV 

Range 

http://www.uscar.org/guest/article_view.php?articles_id=85
NATIONAL RENEWABLE ENERGY LABORATORY 46

http://www.uscar.org/guest/article_view.php?articles_id=85

USABC Goals for Advanced Batteries for EVs

Parameter (Units) of Fully Burdened System Minimum Goals for Long Term 

Commercialization Long Term Goal

Power Density (W/L) 460 600

Specific Power – Discharge, 80% DOD/30 sec (W/kg) 300 400

Specific Power – Regen, 20% DOD/10 sec (W/kg) 150 200

Energy Density – C/3 Discharge Rate (Wh/L) 230 300

Specific Energy – C/3 Discharge Rate (Wh/kg) 150 200

Specific Power/Specific Energy Ratio 2:1 2:1

Total Pack Size (kWh) 40 40

Life (Years) 10 10

Cycle Life – 80% DOD (Cycles) 1,000 1,000

Power & Capacity Degradation (% of rated spec) 20 20

Selling Price – 25,000 units @ 40 kWh ($/kWh) <150 100

Operating Environment (°C) -40 to +50

20% Performance Loss (10% Desired) -40 to +85

Normal Recharge Time 6 hours (4 hours desired) 3 to 6 hours

High Rate Charge 20-70% SOC in <30 min @ 150 W/kg 

(<20 min @ 270 W/kg Desired) 40-80% SOC in 15 min

Continuous Discharge in 1 Hour – No Failure

(% of rated energy capacity) 75 75
NATIONAL RENEWABLE ENERGY LABORATORY

http://www.uscar.org/guest/article_view.php?articles_id=85

USABC Goals for Advanced Batteries for EVs

Parameter (Units) of Fully Burdened System Minimum Goals for Long Term 

Commercialization Long Term Goal

Power Density (W/L) 460 600

Specific Power – Discharge, 80% DOD/30 sec (W/kg) 300 400

Specific Power – Regen, 20% DOD/10 sec (W/kg) 150 200

Energy Density – C/3 Discharge Rate (Wh/L) 230 300

Specific Energy – C/3 Discharge Rate (Wh/kg) 150 200

Specific Power/Specific Energy Ratio 2:1 2:1

Total Pack Size (kWh) 40 40

Life (Years) 10 10

Cycle Life – 80% DOD (Cycles) 1,000 1,000

Power & Capacity Degradation (% of rated spec) 20 20

Selling Price – 25,000 units @ 40 kWh ($/kWh) <150 100

Operating Environment (°C) -40 to +50

20% Performance Loss (10% Desired) -40 to +85

Normal Recharge Time 6 hours (4 hours desired) 3 to 6 hours

High Rate Charge 20-70% SOC in <30 min @ 150 W/kg 

(<20 min @ 270 W/kg Desired) 40-80% SOC in 15 min

Continuous Discharge in 1 Hour – No Failure

(% of rated energy capacity) 75 75

47

Available Energy = 40 kWh at 

C/3 rate 

Cycle Life (full charge depleting) = 

1,000 cycles (150,000 miles) 

Peak Power Discharge 

(10S) = 80 kW 

Cost for Mass Produced System = 

$6,000 ($150/kWh)

Calendar Life at 30°C 

= 10 years
NATIONAL RENEWABLE ENERGY LABORATORY

DOE Energy Storage Goals HEV (2010) PHEV (2015) EV (2020)

Equivalent Electric Range (miles) N/A 10–40 200–300

Discharge Pulse Power (kW) 25 38–50 80

Regen Pulse Power (10 seconds) (kW) 20 25–30 40

Recharge Rate (kW) N/A 1.4–2.8 5–10

Cold Cranking Power @ -30°C (2 seconds) (kW) 5 7 N/A

Available Energy (kWh) 0.3 3.5–11.6 30–40

Calendar Life (year) 15 10+ 10

Cycle Life (cycles) 3,000 3,000–5,000, deep 

discharge 750+, deep discharge

Maximum System Weight (kg) 40 60–120 300

Maximum System Volume (l) 32 40–80 133

Operating Temperature Range (oC) -30 to +52 -30 to 52 -40 to 85

Source: David Howell, DOE Vehicle Technologies Annual Merit Review 

Summary: 

DOE and USABC Battery Performance Targets

48
NATIONAL RENEWABLE ENERGY LABORATORY

Introduction to NREL

Introduction to HEVs, PHEVs and EVs

Battery Technologies for HEVs, PHEVs & EVs

Battery Requirements for EDVs

Concluding Remarks

49

Outline of the Presentation
NATIONAL RENEWABLE ENERGY LABORATORY

Integrating Cells into Packs

50

• Safety (abuse tolerance, one cell will have an event) 

• Cost/Value

• Long life/Durable

• Manufacturability

• Recyclability

• Diagnostics

• Maintenance/Repair

• Packaging – Structural and connections

• Thermal Management – life (T), performance (T), safety

– Impedance change with life – impact on thermal management 

and design for end of life

• Electrical Management – balancing, performance, life, 

safety 

• Control/Monitoring

– Gauge (capacity, power, life)

Cylindrical vs. flat/prismatic designs

Many small cells vs. a few large cells 
NATIONAL RENEWABLE ENERGY LABORATORY

Many small cells 

– Low cell cost (commodity market)

– Improved safety (faster heat rejection)

– Many interconnects

– Low weight and volume efficiency

– Reliability (many components, but some redundancy) 

– Higher assembly cost

– Electrical management (costly)

Fewer large cells

– Higher cell cost

– Increased reliability due lower part count

– Lower assembly cost for the pack

– Higher weight and volume efficiency

– Thermal management (tougher)

– Safety and degradation in large format cells

– Better reliability (lower number of components)

51

Battery Packaging?

Source: Valance 

Technologies

Source: EnergyCS

Source: Matt Keyser (NREL)

Source: Saft America
NATIONAL RENEWABLE ENERGY LABORATORY

Battery Packs in Some EDVs

52

http://autogreenmag.com/tag/chevroletvolt/page/2/

Chevy Volt Nissan Leaf

http://inhabitat.com/will-the-nissan-leaf-battery-deliver-all-itpromises/

http://www.toyota.com/esq/articles/2010/Lithium_Ion_Batte

ry.html

Prius PHEV

http://www.caranddriver.com/news/car/10q4/2012_mitsubi

shi_i-miev_u.s.-spec_photos_and_infoauto_shows/gallery/mitsubishi_prototype_i_miev_lithiumion_batteries_and_electric_drive_system_photo_19

i-MiEV

http://www.metaefficient.com/cars/ford-focus-electricnissan-leaf.html

Ford Focus

http://www.ibtimes.com/articles/79578/20101108/sblimotive-samsung-sdi-chrysler-electric-car.htm

Fiat 500 EV
NATIONAL RENEWABLE ENERGY LABORATORY 53

Investments in Factories to Reduce Battery Cost

(based on Recovery and Reinvestment Act of 2009)

Source: David Howell, Energy Storage Program Overview, 2010 DOE Annual Merit Review
NATIONAL RENEWABLE ENERGY LABORATORY

The energy efficiency of light-duty vehicles is about 200 to 400 

Wh/mile

– 5 to 12 kWh battery for 30 miles

– 2-Second power: 30 to 60 kW

– P/E from 2 to 15

Sprinter PHEV consumes about 600 Wh/mile in charge-depleting 

(CD) mode

Heavy-duty vehicles could consume from 1,000 to 2,000 

Wh/mile

– 30 to 60 kWh battery for 30-mile range

– Volume, weight, and cost are big issues

– Thermal management is a concern

54

Battery Energy Requirements for Heavy-Duty EDVs
NATIONAL RENEWABLE ENERGY LABORATORY

Examples of Medium- and Heavy-Duty EDVs

55

http://green.autoblog.com/photos/fedex-hybrid-truck/

http://green.autoblog.com/2007/05/21/walmart-receives-its-first-peterbilt-hybrid-bigrig/

http://www.greenoptions.com/forum/thread/20

29/coke-uses-hybrid-electric-trucks

http://www.gizmag.com/worlds-first-hybrid-refuse-truck-volvo-sweden/9131/

http://articles.sfgate.com/2009-12-06/business/17182903_1_hybrid-garbage-trucks-volvogroup

http://green.autoblog.com/2008/01/22/dc-auto-show-1-732-more-orders-for-gm-hybrid-buses/

http://www.hybridcars.com/news/greening-massivegovernment-vehicle-fleet-28337.html http://www.hybridcars.com/fleets/part-growing-trendups-adds-200-hybrid-trucks-28035.html
NATIONAL RENEWABLE ENERGY LABORATORY

Examples of Medium- and Heavy-Duty EDVs and Their 

Batteries

56

http://www.ecogeek.org/automobiles/3375-electric-garbage-trucks-coming-toparis?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+EcoGeek+%28EcoGeek%29

http://www.dieselpowermag.com/features/trucks/1103dp_artisan_vehi

cle_systems_diesel_hybrid_big_rig/photo_06.html

http://www.hybridcars.com/hybrid-car-battery http://www.electricenergyonline.com/?page=show_news&id=138652

Courtesy of Argonne National Laboratory: 

http://www.transportation.anl.gov/media_center/transp

ortation_images/battery_images.html
NATIONAL RENEWABLE ENERGY LABORATORY

An Example of an Investigation to Evaluate MediumDuty Electric Drive Vehicles

57

For more information, see the 

complete conference paper, 

NREL/CP-5400-49253
NATIONAL RENEWABLE ENERGY LABORATORY 58

Example Results Comparing Different Electrification Options for a 

Medium-Duty Vehicle

Source: Rob Barnitt, EVS-25 Presentation, Shenzhen, China, Nov, 2010 

Battery and fuel costs dominate economics; lowering battery costs is critical to EDV penetration.

Optimizing route (intensity and distance) selection can minimize petroleum use and costs.
NATIONAL RENEWABLE ENERGY LABORATORY 59

Concluding Remarks

• There are many types of electric drive technologies and thus battery 

solutions

• Batteries with high power-to-energy ratios are needed for HEVs

• Batteries with low power-to-energy ratios are needed for EVs and 

PHEVs

• NiMH batteries would be the technology of choice for HEVs for the next 

5 years, and then they will be gradually replaced by Li-ion

• Li-ion batteries have the power and energy densities for PHEV and EV 

applications, but cost is an issue for mass-produced adoption

• There are a number of Li-ion chemistries with prismatic or cylindrical 

formats that could be mass produced in the market

• Difficult to predict technology winner

• Many companies are performing R&D and high-volume manufacturing in the 

United States, Japan, Korea, and China

• The key barriers to commercialization of PHEVs and EVs are battery 

life, packaging and cost (Recovery Act funding is expected to reduce battery cost)

• Battery technologies being developed for light duty vehicles can be 

used for medium- and heavy-duty applications
NATIONAL RENEWABLE ENERGY LABORATORY

Acknowledgments

60

DOE Program Support

– Dave Howell

– Tien Duong

– Brian Cunningham

NREL Technical Support

– Shriram Santhanagopalan 

– Anne Dillon

– Matt Keyser

– Kandler Smith 

– Gi-Heon Kim

– Jeremy Neubauer
NATIONAL RENEWABLE ENERGY LABORATORY

nrel.gov/vehiclesandfuels/energystorage/

Thank You!

ahmad.pesaran@nrel.gov

61