EVS28KINTEX, Korea, May 3-6, 2015

Development of accelerated cycle life test method for (hybrid) electric

vehicle battery module

Jung Eun Hyun1, Younglong Kim, Taeeun KimKorea Automotive Technology Institute, 303 Pungse-ro, Pungse-myeon,

Dongnam-gu, jehyun@katech.re.kr

Contents

I. Status of International standardization status of Li ion traction

battery.

II. Test method

III. Evaluation of battery module

IV. Battery cycle life estimation

V. Summary

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1. ISO 12405 : Electric road vehicles – Test specificationfor Lithium-ion traction battery systems

- ISO 12405-1 (published in 2011-12) : High powerapplications

- ISO 12405-2 (published in 2012-06) : High energyapplications

- ISO 12405-3 (at FDIS stage) : Safety performancerequirements

2. ISO/IEC PAS 16898 (published) : Electric roadvehicles –Battery system design – Requirements ondimensions for lithium-ion cells for vehicle propulsion

3. ISO 18300 (DIS) : Electrically propelled road vehicles— Specifications for lithium-ion traction battery systemcoupled with other types of battery and capacitor

1. IEC 62660: Secondary lithium-ion cells for the

propulsion of electric road vehicles

- IEC 62660-1 (published in 2010-12) : performancetesting

- IEC 62660-2 (published in 2010-12) : Reliability and

abuse testing

- IEC 62660-3 (at CD stage) : Safety requirements

§ ISO TC22(road vehicles) SC21(Electrically propelled road vehicles) WG3 lithium ion traction batteries

§ IEC TC21(Secondary cell/batteries)§ IEC TC 69 Electric road vehicles and electric

industrial trucks§ IEC TC21/JWG69 Li : Lithium for automobile/

automotive applications

Status of International standardization status of Li ion traction battery.

전기자동차용 배터리 국제 표준 개발 현황Status of International standardization status of Li ion traction battery.

ISO TC22/SC37/WG01 1st meeting 2015-03-02/3, Detroit

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ISO TC22 12405-1, 2, Lithium ion traction battery part 1–high power application, Part 2-high energy application62660-1, Lithium ion cells, part 1 – performance testing

Battery test manuals – plug-in, electric, hybrid electric battery system

CHINA GB/ QC

D 708, Ni-MH battery system test for EV

Accelerated cycle life test estimation of battery module

• Battery module temperaturechange with different test cyclepattern

• Measuring of the capacityand internal resistancedegradation with differenttest method

• Estimation of cycle life ofbattery module

- Single temperature factor

IEC TC21

U.S.A. USABC/SAE

JAPAN JEVS

International Standard

Nation/RegionStandard

KOREA KS

GB/Z18333.1, QC/T143, Lithium ion batteries for electric vehicles

ISO 12405-2 부합화 예정

USABC : United States Advanced Battery ConsortiumJEVS : Japanese Electric Vehicle SystemGB : GuobiaoQC : Quality Control

Status of International standardization status of Li ion traction battery.

Charge and discharge system

Chamber

Control ComputerPulse generator

DAQ data logger

Test module

<A module> <B module>

Model Module Nominal Vol. Vmax Vmin Capacity/cell Imax (5C)

A 2S2P 7.4 8.4 5 65 325

B 13S 48.6 54.6 39 31 155

Test method

<Charge discharge profile @ 25oC>

Charge resistance (Rc) Discharge resistance (Rd)

SOC 80 SOC 50 SOC 20 SOC 80 SOC 50 SOC 20

25oC 0.0020 0.0021 0.0022 0.00235 0.00214 0.00222

40oC 0.00186 0.00168 0.0019 0.00169 0.00179 0.00179

0oC 0.00388 0.00362 0.00393 0.00372 0.00366 0.00387

-20oC - - 0.00969 0.00729 0.0072 0.00684

Discharge resistance (Rd)

Charge resistance (Rc)Resistance

Resistance

IEC 62660-1

Evaluation of A battery module/ capacity & power/ resistance

40oC Charge resistance

40oC Discharge resistance

0oC Charge resistance

0oC Discharge resistance

25oC Charge resistance

25oC Discharge resistance

-20oC Charge resistance

-20oC Discharge resistance

ØAt 25oC & 40oC, the charge/ discharge resistance is similar but in low temperature the resistance value is increased drastically

Evaluation of A battery module/ Resistance by IEC 62660 method

Ø Measured voltage profile by ISO 12405-2Ø Same

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1 501 1001 1501 2001

SOC 90SOC 70SOC 50SOC 35SOC 20

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1 501 1001 1501 2001

SOC 90SOC 70SOC 50SOC 35SOC 20

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1 501 1001 1501 2001

SOC 90SOC 70SOC 50SOC 35SOC 20

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1 501 1001 1501 2001

SOC 90SOC 70SOC 50SOC 35SOC 20

Origin data 추가<25oC> <40oC>

<0oC> <-18oC>

Evaluation of A battery module/ Resistance by ISO 12450-1 method

<25oC, discharge resistance according to time> <40oC, discharge resistance according to time >

<0oC, discharge resistance according to time > <-20oC, discharge resistance according to time >

Resistance

Resistance

Resistance

Resistance

Evaluation of A battery module/ Resistance by ISO 12450-1 method

Charge resistance (Rc) Discharge resistance (Rd)

SOC 80 SOC 50 SOC 20 SOC 80 SOC 50 SOC 20

25oC 0.0255 0.0254 0.0295 0.0257 0.0261 0.0355

40oC 0.0171 0.0175 0.0209 0.0180 0.0179 0.0288

0oC 0.0759 0.0734 0.0793 0.0554 0.0560 0.0503

-20oC 0.0969 0.0729 0.072 0.0684

Resistance

Resistance

Evaluation of B battery module/ capacity & power/ resistance

<Charge discharge profile @ 25oC>

Discharge resistance (Rd)

Charge resistance (Rc)

Evaluation of B battery module/ capacity & power/ resistance

40oC Charge resistance

40oC Discharge resistance

0oC Charge resistance

0oC Discharge resistance

25oC Charge resistance

25oC Discharge resistance

-20oC Charge resistance

-20oC Discharge resistance

ØAt 25oC & 40oC, the charge/ discharge resistance is similar but in low temperature the resistance value is increased drastically

Without fan operation, the distribution of cell temperature is about 10oC.It is needed to control the cell temperature ±2oC by Fan operation, and the 4oCis acceptable value in battery module and battery system.

USABC pattern 12405-2 pattern

Evaluation of A battery module/ cell temperature distribution by test pattern

0 5 10 15 20 25 3070

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Resi

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crea

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Capa

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Aging Time (w)

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35oC capacity degradation & resistance increase

ØThe Fitting value of capacity degradation is differed according to test time.ØOver 4 months, it comes to similar with the real capacity degradation.Ø The test is on going

Life estimation of A battery module

<출처 : Battery Calendar life Estimator manual revision1>

<Linearizable degradation model>- Single stress factor (temperature)

<출처 : Battery Calendar life Estimator manual revision1>

- multiple stress factors

Life estimation

Summary

• Many countries also have developed the test method to evaluate precisely the lithium ion battery’s calendar life and cycle life

• To compare and calculate the cycle degradation irrespective of the national characteristics, IEC/ISO method is referred

• The difference of temperature of cells in module is controlled ±2oC

• The cycle life estimation is on going, and the test period is needed at least 4 months.