The initial simulation on characteristic of lithium ion … initial simulation on characteristic of...

The initial simulation on characteristic of lithium ion cells using COMSOL soft

Liu Xingjiang，Wang Songrui，Lu lili

National Key Lab of Power Sources, Tianjin Institute of Power Sources

2010.10.28，Beijing

Presented at the COMSOL Conference 2010 China

http://www.comsol.com/conf_cd_2011_cn

Want to do

Simulation on charge-discharge behavior of lithium ion cells

Simulation on thermal and safety of lithium ion cells

Design for lithium ion cells – collector, stress

Simulation on lithium ion cells

Simulation on fuel cells Simulation on metal-air cells Simulation on solar cell Design for material

Why？

For lithium-ion batteries, the risk of exploding has restricted the application

Thermal simulation is a useful way to understand and design safer batteries ！

Initial simulation

Electrochemical-thermal simulation on lithium-ion cells Simple simulation J. Newman model R. E. White model

Thermal simulation on lithium-ion cells Adiabatic test Oven test

Others Electric current and temperature distribution on collector

Electric current and temperature distribution on joint

Stretch and stress

Electrochemical-thermal simulation

Simple simulation

Temperature distribution at 1200s

0 200 400 600 800 1000 1200298

300

302

304

306

308

310

312

314

Tem

pera

ture

/K

Time/s

Physical models：

Heat transfer or Heat transfer -Static electric

Parameter：

Resistance/Conductance，dU/dT, Heat transfer coefficient，Thermal capacity ，Heat conduction coefficient ， Density

18650 cell

discharged at

3A for1200s

J. Newman model

Physical models ：

PDE（2）， Diffusion（2）， Heat transfer

loca

effiS 11

loca

effeff

iSctc

f

F

RT

2

2

222 ln1

ln

ln1

2

tF

iScD

dt

dc locaeff122

22

U

RT

FU

RT

Fccckci ca

locc

aa

212111

max

12 expexp

QTKt

TC p

)(

22

2

2

22211121

ln1ln

ln1

2

ctc

f

F

RT

T

UTiSUiSQ

eff

effeff

localoca

0))((1

11

2

2

1

c

rDr

rrdt

dc

p

p

pp

Parameter ：

Porosity， Radius， Surface area，dU/dT ， Equilibrium potential ， Diffusion coefficient ( liquid, solid), Conductance (liquid, solid)，Reaction rate coefficient, Heat transfer coefficient，Thermal capacity ，Heat conduction coefficient ， Density

Simulation the progress of charge-discharge，to understand the physical and chemical changes in cells

Expressions:


2430 coin cell discharged at 9A/m2 for 1500s，rest for 300s, and charged at 9A/m2 for 1500s

Cell voltage

0 1000 2000 3000 40003.8

3.9

4.0

4.1

4.2

4.3

Pot

entia

l/V

Time/s


J. Newman model

0 1000 2000 3000 4000273

274

275

276

277

278

Tem

pera

ture

/K

Time/s

Cell temperature


J. Newman model

Positive concentration


J. Newman model

Negative concentration

Electrolyte concentration

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.53.0

3.2

3.4

3.6

3.8

4.0

4.2

Pot

entia

l/V

Capacity/mAh

Newman model 1A/m2

5A/m2

10A/m2

20A/m2

40A/m2

0 5 10 15 20 25 30 35 40

2.6

2.8

3.0

3.2

3.4

3.6

Current density/Am-2

Dis

char

ge c

apac

ity/m

Ah

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

274

276

278

280

282

284

286

288

290

292

Tem

pera

ture

/K

Capacity/mAh

Newman model 1A/m2

5A/m2

10A/m2

20A/m2

40A/m2

0 5 10 15 20 25 30 35 40

274

276

278

280

282

284

286

288

290

292

Tem

pera

ture

/K


Discharged at different current

densities


J. Newman model

loca

effiS 11

loca

effeff

iSctc

f

F

RT

2

2

222 ln1

ln

ln1

2

tF

iScD

dt

dc locaeff122

22

U

RT

FU

RT

Fccckci ca

locc

aa

212111

max

12 expexp

QTKt

TC p

)(

22

2

2

22211121

ln1ln

ln1

2

ctc

f

F

RT

T

UTiSUiSQ

eff

effeff

localoca

F

iS

t

c loca

ave31

1

115FD

ricc

plocave


R. E. White model Simulate the progress of charge-discharge，to understand the physical and chemical changes in cells

Parameter ：

Porosity， Radius， Surface area，dU/dT ， Equilibrium potential ， Diffusion coefficient ( liquid, solid), Conductance (liquid, solid)，Reaction rate coefficient, Heat transfer coefficient，Thermal capacity ，Heat conduction coefficient ， Density

Expressions:

Physical models ：

PDE（3）， Diffusion（1）， Heat transfer

0 1000 2000 3000 4000

3.8

3.9

4.0

4.1

4.2

Pot

entia

l/V

Time/s


R. E. White model

2430 coin cell discharged at 9A/m2 for 1500s，rest for 300s, and charged at 9A/m2 for 1500s

Cell voltage

Cell temperature

0 1000 2000 3000 4000273

274

275

276

277

Tem

pera

ture

/K

Time/s


R. E. White model


R. E. White model

Positive/negative concentration


0.0 0.5 1.0 1.5 2.0 2.5 3.03.0

3.2

3.4

3.6

3.8

4.0

4.2

Pot

entia

l/V

Capacity/mAh

White model 1A/m2

5A/m2

10A/m2

20A/m2

40A/m2

0.0 0.5 1.0 1.5 2.0 2.5 3.0

274

276

278

280

282

284

286

288

290

292

Tem

pera

ture

/K

Capacity/mAh

White model 1A/m2

5A/m2

10A/m2

20A/m2

40A/m2

0 5 10 15 20 25 30 35 40

2.75

2.80

2.85

2.90

2.95

3.00

3.05

Cap

acity

/mA

h

Current density/Am-20 5 10 15 20 25 30 35 40

274

276

278

280

282

284

286

288

290

292

Tem

pera

ture

/K



R. E. White model

Discharged at different current

densities

Thermal simulation

Electrode material Thermal test Date &

equation Simulation Cell models

Anode/Cathode

Full/half

charge/discharge

With electrolyte DSC &

ARC

Kinetics calculation

Comparison with

experiment date

Cell structure & parameter

Simulation of adiabatic & oven test

Result

QTKt

TC ipii

)(

i

iii RHQ

ana xxRT

EA

dt

dx)1(exp 11

1

ana xxRT

EA

dt

dx)1(exp 22

2

Rdt

dx

……..

Parameter ：

Heat transfer coefficient，Thermal capacity ，Heat conduction coefficient ， Density, Activation energy, frequency factor , enthalpy，reaction order

6 group of reaction rate expressions used in the example：

Positive 1， Negative 2， Electrolyte 3

Thermal simulation

Simulate the thermal behavior and safety of lithium ion cells

Expressions:

Physical models ：

PDE（n），Heat transfer (1)

0 10000 20000 30000 40000 50000 60000360

390

420

450

480

510

Tem

pera

ture

rate

/K/s

Temperature Temperature rate

Time/s

Tem

pera

ture

/K

0.0

0.8

1.6

2.4

3.2

4.0

Temperature

Li-Co-O/C cell

363K

Thermal simulation

Adiabatic

Electrode concentration

Li-Co-O/C cell

363K

360 380 400 420 440 460 480 500 520

0.0

0.8

1.6

2.4

3.2

4.0

370 380 390 400 410 420 430 440 450

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.00000

0.00005

0.00010

0.00015

Temperature

Rea

ctio

n ra

te/s

-1

Temperature/K

Tem

pera

ture

rate

/K/s

0.000

0.002

0.004

0.006

0.008

Positive Negative Electrolyte SEI Gasifing Solvent

Thermal simulation

Adiabatic


LiFePO4/C cell

398K

0 10000 20000 30000 40000 50000 60000 70000

420

450

480

510

540

Tem

pera

ture

rate

/K/s


Time/s

Tem

pera

ture

/K

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Temperature

Thermal simulation

Adiabatic

LiFePO4/C cell

398K

400 420 440 460 480 500 520 540 560

0.0

0.3

0.6

0.9

1.2

1.5

400 420 440 460 480 500

0.00

0.03

0.06

0.09

0.12

0.15

0.00000

0.00003

0.00006

0.00009

0.00012

0.00015 Temperature

Rea

ctio

n ra

te/s

-1

Temperature/K

Tem

pera

ture

rate

/K/s

0.000

0.001

0.002

0.003

0.004

0.005

0.006

Positive Negation Electrolyte SEI Gasifing Solvent

Thermal simulation

Adiabatic

Electrode concentration Electrolyte

concentration

LiFePO4/Li-Ti-O cell

413K

Temperature

0 10000 20000 30000 40000 50000 60000410

420

430

440

450

460

470

480

490

Tem

pera

ture

rate

/K/s


Time/s

Tem

pera

ture

/K

0.00

0.01

0.02

0.03

0.04

0.05

Thermal simulation

Adiabatic


413K

410 420 430 440 450 460 470 480 490

0.00

0.01

0.02

0.03

0.04

0.05

420 430 440 450 460 470 480 490

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

0.0000

0.0001

0.0002

0.0003

0.0004

Rea

ctio

n ra

te/s

-1

Temperature

Temperature/K

Tem

pera

ture

rate

/K/s

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

Positive Negative Electrolyte Surface Gasifing Solvent

Thermal simulation

Adiabatic


concentration

Oven test

0 2000 4000 6000 8000

300

350

400

450

500

Tem

pera

ture

rate

/K/s


Time/s

Tem

pera

ture

/K

0.0

0.4

0.8

1.2

1.6

2.0

Temperature

Li-Co-O/C cell

413K

Thermal simulation

Li-Co-O/C cell

413K

300 330 360 390 420 450 480

0.0

0.3

0.6

0.9

1.2

1.5

1.8

380 390 400 410 420 430 440 450 460

0.00

0.03

0.06

0.09

0.12

413K

0.00000

0.00003

0.00006

0.00009

0.00012

0.00015

Rea

ctio

n ra

te/s

-1

Temperature

Temperature/K

Tem

pera

ture

rate

/K/s

413K

0.000

0.001

0.002

0.003

0.004


Thermal simulation Oven test


concentration

Temperature

LiFePO4/C cell

468K

0 1500 3000 4500 6000 7500 9000

300

350

400

450

500

550

Tem

pera

ture

rate

/K/s


Time/s

Tem

pera

ture

/K

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35


300 330 360 390 420 450 480 510 540

0.00

0.05

0.10

0.15

0.20

0.25

0.30 Temperature

Rea

ctio

n ra

te/s

-1

Temperature/K

Tem

pera

ture

rate

/K/s

468K

0.0000

0.0004

0.0008

0.0012

0.0016

0.0020

0.0024


LiFePO4/C cell

468K



concentration

Temperature


468K

0 1500 3000 4500 6000 7500 9000

300

330

360

390

420

450

480

510

Tem

pera

ture

rate

/K/s


Time/s

Tem

pera

ture

/K

-0.04

0.00

0.04

0.08

0.12

0.16

0.20



468K

300 330 360 390 420 450 480 510-0.05

0.00

0.05

0.10

0.15

0.20

Rea

ctio

n ra

te/K

/s Temperature

Temperature/K

Tem

pera

ture

rate

/K/s

468K

0.00000

0.00015

0.00030

0.00045

0.00060

0.00075

Positive Negative Electrolyte Surface Gasifing Solvent



concentration

Electric current and temperature distribution on collector

Electric current

18650 copper collector 1A 10s

Physical models： Heat transfer , Static electric

Parameter： Conductance，, Heat transfer coefficient，Thermal capacity ，Heat conduction coefficient ， Density

Temperature


Temperature

Physical models： Heat transfer , Static electric

Parameter： Conductance，, Heat transfer coefficient，Thermal capacity ，Heat conduction coefficient ， Density

80A for 1200s

Electric current grads Electric current arrow Temperature(1200s)


Stretch and stress 18650 cell

Positive expanding 3% Negative expanding 5%

Physical models： Structure

Parameter： Young’s modulus，Poisson’s ratio

Conclusion

Simulation on charge-discharge behavior of lithium ion cells ： the precision depends on models and conditions；

Simulation on thermal and safety of lithium ion cells：availability, to forecast the cells safety under different conditions！

Design for lithium ion cells structure：To direct the design for cell with high capacity and high rate, by analyzing the collector , stress, et al

Using COMSOL soft

The initial simulation on characteristic of lithium ion … initial simulation on characteristic of...

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