A High-Performance PHEV Battery Pack

PI: Mohamed Alamgir and Geun-Chang Chung

LG Chem Power / LG Chem

May 16, 2012 Project ID: ES002

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

LG Electronics LG Display LG Innotek LG Siltron … 9 Companies

LG U+ LG CNS LG Solar Energy LG International … 33 Companies

Electronics Telecom & Service

Established Lucky Chemical Industrial Corp. in 1947

Changed its name from Lucky Gold Star to LG in 1995

LG Chem LG Hausys LG Healthcare LG Life Sciences … 13 Companies

Chemical

Sales (2011) – $124B Employees – 210,000

LG Group at a Glance

ABS/EP

NCC/Polyolefin

PVC/Rubber

Acrylate

LCD Polarizer

LCD Glass

OLED Materials

Color Filter

Lithium-Ion Batteries for

- Mobile Phone, Laptop, Power Tool

- Hybrid & Electric Vehicles

- ESS

Energy

Solution(10%)

Petro- chemicals

(75%)

IT & Electronics

Materials (15%)

$ 19.5 B (2011) IT &

Electronics Materials

(17%)

Petro- chemicals

(23%)

Energy

Solution(60%)

Revenue R&D Expense

Energy Solution Petrochemicals IT & Electronics Materials

LG Chem at a glance

Battery Pack Concepts, Design and Prototype Builds

Battery Management Systems Sales and Customer Support

LGCPI

$300M+ investment with ARRA funding

Groundbreaking: Summer 2010

Production begins in 2012

LGCMI

Troy, MI Sales & Pack R&D

Holland, MI Cell Manufacturing

Cell Structure: Unique Stack- and-Fold Design

Positive terminal

Negative terminal

Lead film (insulation tape)

Stack and Folded cell

Bi-cell Laminated film

SRSTM

Stacking of Plates & Folding

SRSTM provides superior abuse-tolerance By improved mechanical and thermal stability By preventing internal short circuit By providing lower shrinkage

Nano scale Ceramic Particles

Micro porous Polyolefin film

Proprietary Safety Reinforcing Separator (SRSTM)

Significantly higher puncture strength than conventional separator

• Project Start: April 1, 2011 • Project End: March 31, 2013 • Percent complete: 50%

• Total project funding: $9.6M • DOE share: $4.8M • Contractor share: $4.8M • Funding for FY11: $3.2M

Timeline

Budget

Barriers

• LG Chem, INL, SNL, NREL

• Project lead: LGCPI

Partners

Overview of Current Program

• Specific Energy and Power

• Cycle- and Calendar-life

• Cell Cost goal of <$200/kWh

• Efficient Refrigerant-to-Air cooling system

Develop a cell suitable for use in the PHEV-40 Mile program using next generation, high capacity Mn-rich cathode materials.

A key goal of the program is to lower the pack cost to close to the $3400 target.

Optimize the Refrigerant-to-Air cooling system we have developed in our previous program with respect to mass, volume, cost and power demand.

Deliver cells and battery packs to USABC for testing.

Objectives

PHEV 40-Mile Battery Pack Goals

Characteristics at EOL Units

Requirements for

40-MileProgram

Reference Equivalent Electric Range Miles 40Peak Pulse Discharge Power, 2 Sec kW 46Peak Pulse Discharge Power, 10 Sec kW 38Peak Regen Pulse Power, 10 Sec kW 25Available Energy, CD4 mode, 10kW rate kWh 11.6

Available Energy, CS4 mode kWh 0.3

Minimum round-trip Energy Efficiency5 % 90Cold Cranking Power at -30°C, 2 sec / 3 pulses (2-10-2-10 2)

kW 7

Cycles; 5000

MWh 58CS HEV Cycle Life, 50Wh Profile Cycles 300,000Calendar life at 35°C Years 15Maximum System Weight Kg 120Maximum System Volume Liters 80Maximum Operating Voltage Vdc 400Minimum Operating Voltage Vdc >0.55VmaxMaximum Self-Discharge Wh/da

y50

1.4

(120V/15A)Maximum System Production Price @100k units/year US$ $3,400

CD Life / Discharge throughput

System Recharge Rate at 30°C kW

Study high capacity, Mn-rich, layered-layered cathode materials from multiple vendors.

Characterize and Improve the performance, life and abuse-tolerance of Mn-rich cathode materials.

Optimize, fabricate and deliver battery packs based on Refrigerant-to-Air cooling system we have developed in our earlier USABC Program.

Approach/Strategy

Mn-rich cathode materials from two vendors have been evaluated.

Built cells with careful control of various cell fabrication parameters/processes such as electrode formulations, formation protocol etc to identify conditions optimum for performance and life.

Studied the effect of operational voltage ranges on energy, power and life.

Studied the effect of electrolyte additive on life.

Technical Accomplishments/Results

Our 1st generation Refrigerant-to-Air pack has been redesigned and is being optimized with respect to Weight, Volume, Power demand.

Cell- and Module level thermal studies have been

carried out to examine the efficacy of this cooling concept.

First prototype packs have now been built and are being evaluated for cooling efficiency.

Technical Accomplishments/Results

Baseline studies with Mn-rich cathodes show capacities as high as ~ 250 mAh/g at RT.

Strong dependence on rate.

0 50 100 150 200 250 3002.5

3.0

3.5

4.0

4.5

Volta

ge (V

)

Discharge capacity (mAh/g)

0.1C 1C

0 50 100 150 200 250 3002.5

3.0

3.5

4.0

4.5

Volta

ge (V

)Discharge capacity (mAh/g)

0.1C 1C

Sample A Sample B

Results- continued……

Rapid increase in DC resistance at low SOCs. This can limit the usable SOC range for PHEV

applications.

Results- continued……

0 10 20 30 40 50 60 70 80 90 1000.0

2.0

4.0

6.0

8.0

Resi

stan

ce (m

ohm

)

SOC (%)

Discharge resistance Regen resistance

Co Mn Ni 24 ppm 145 ppm 19 ppm

High voltage operation results in severe Mn dissolution in regular electrolyte.

Need to identify suitable electrolyte

Results- continued……

0 20 40 60 80 100 120 140 1600.0

20.0

40.0

60.0

80.0

100.0

25oC 4.5V~2.0V 1C/2C cycle

Norm

aliz

ed c

apac

ity (%

)

Cycle

Max charge voltage has a strong influence on cycle-life.

45oC 1C/2C cycle

Results- continued……

0 50 100 150 200 250 300 350 400 4500

20

40

60

80

100

4.5V4.45V 4.35V

4.4V

4.1V

Norm

aliz

ed c

apac

ity (%

)

Cycle

4.5V 4.45V 4.4V 4.35V 4.24V 4.1V

4.24V

Discharge cut-off voltage also has significant effect on cycle-life.

Results- continued……

0 50 100 150 200 250 300 350 4000

20

40

60

80

100No

rmali

zed

capa

city (

%)

Cycle

4.4V~2.0V 4.4V~3.18V

45oC 1C/2C cycle

Electrolyte additives enhance cycle-life.

45oC 4.5V~2.0V 1C/2C cycle

0 20 40 60 80 100 120 140 160 180 2000

1020

30

4050

60

7080

90

100

Nor

mal

ized

cap

acity

(%)

Cycles

Ref. Ref. + Add#5 Ref. + Add#7 Ref. + Add#5 & Add#7

Results- continued……

Requires refrigerant loop; but: Avoids coolant fill and maintenance, obviates need for

complex coolant manifolds and risks of leaking.

Phase I- Two thermal zones: Refrigerated compartment (cells, evaporator, fan) Ambient compartment (controls, compressor, condenser,

fan)

Results: Refrigerant Cooling System

Thermal

Results: Phase II Cooling System- integrated design

Electronics

Cells

A refrigerant loop is used to cool the cold-plate inside the battery pack which in turn is attached to fins sandwiched between the cells.

24.7

25.8

26.326.5

26.3 26.426.1

25.9

25.1

20.0

21.0

22.0

23.0

24.0

25.0

26.0

27.0

28.0

29.0

30.0

CT1 CT2-3 CT4-5 CT6-7 CT8-9 CT10-11 CT12-13 CT14-15 CT16

Tem

pera

ture

(C°)

Thermocouple Name

10Nov2011 USABC Module Thermal Testing Test 4--Repeated US06 Drive Cycles (derated) from 90%-20%SOC, Module at Room Temp, 15°C cold plate, 1mm Al fin - 90deg bend-

TC Cell Temps at Worst dT(1.8C°)

Results: Cooling System- Module Level Testing

US06 Drive Profile SOC range = 90- 20% 25oC, Cold-plate at 15oC Max ∆T among cells : ~2o C

Efficient cooling- satisfies target

21.2

21.1

21.0

20.9

20.8

21.0 21.0

20.9

21.1

20.0

20.2

20.4

20.6

20.8

21.0

21.2

21.4

21.6

21.8

22.0

CT1 CT2-3 CT4-5 CT6-7 CT8-9 CT10-11 CT12-13 CT14-15 CT16

Tem

pera

ture

(C°)

Thermocouple Name

14Nov2011 USABC Module Thermal Testing Test 5--Repeated UDDS Highway Drive Cycle (5kW rms) from 90-20%SOC, room temp ambient, 15°C cold plate, 1mm Al fin

with 89* bend -TC Cell Temps at Worst dT (0.4C°)

Results: Cooling System- Module Level Testing UDDS Drive Profile SOC range = 90- 20% 25oC, Cold-plate at 15oC Max ∆T among cells : ~0.5o C

Future Work

Studies to improve power and life will include, among others

Surface-modified cathodes Different electrolyte compositions/additives.

Delivery of cells to National Labs for evaluation with

improved power and life.

Testing of prototype packs under various heat-loads using different driving profiles and additional optimization of the thermal system.

Delivery of packs to National Labs.

Project Start: Jan 1, 2008 Project End: March 31, 2010 Percent complete: 100

Cycle-life Calendar-life Cold-Cranking Power Efficient/reliable

thermal management system

• Total project funding: $12.7M

Timeline

Budget

Barriers Addressed

• LG Chem, INL, SNL, NREL

• Project lead: LGCPI

Partners

Overview of Last PHEV Program

Project Start: Jan 1, 2008 Project End: March 31, 2010

Total project funding: $12.7M

Timeline

Budget

Cell/ Approach

• Cycle-life improved significantly: 5000 cycles

• Calendar-life needs additional improvement

Key Results

Highlights of Past PHEV Program

Barriers addressed

Cycle-life Calendar-life Abuse-tolerance

• Oxide-blend cathode/graphite

• Refrigerant-to-air cooling system

Project Start: Sep 1, 2006 Project End: Feb 29, 2008

Total project funding: $6.3M

Timeline

Budget

Cell/ Approach

• Cycle-life improved significantly: > 550k cycles

• Calendar-life: > 10 yrs • Excellent abuse-

tolerance

Key Results

Highlights of Past HEV Program

Barriers addressed

Cycle-life Calendar-life Cold-Cranking Power

• Spinel/Hard-Carbon • Approaches used: coatings, dopants, use of electrolyte additives

OEM Vehicle Cell GM Chevy Volt PHEV Ford Focus BEV PHEV Hyundai Sonata

Hybrid HEV

Use of LGC’s Cells in Production Vehicles

These cells benefitted directly from the development programs LGCPI had with USABC.

LGCPI team (Paul Laurain, Satish Ketkar, Jongmoon Yoon and Kwangho Yoo)

LG Chem team (Geun-Chang Chung, Song-Taek Oh, Jaepil Lee)

USABC for their financial and technical support in course of these programs.

Paul Groshek- Program Manager

INL (Jeff Belt), NREL (Ahmad Pesaran, Kandler Smith), LBNL (Vince Battaglia) and SNL (Chris Orendorff) for invaluable technical support

Acknowledgements