The initial simulation on characteristic of lithium ion … initial simulation on characteristic of...
Transcript of 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
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:
Electrochemical-thermal simulation
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
Electrochemical-thermal simulation
J. Newman model
0 1000 2000 3000 4000273
274
275
276
277
278
Tem
pera
ture
/K
Time/s
Cell temperature
Electrochemical-thermal simulation
J. Newman model
Positive concentration
Electrochemical-thermal simulation
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
Current density/Am-2
Discharged at different current
densities
Electrochemical-thermal simulation
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
Electrochemical-thermal simulation
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
Electrochemical-thermal simulation
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
Electrochemical-thermal simulation
R. E. White model
Electrochemical-thermal simulation
R. E. White model
Positive/negative concentration
Electrolyte 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
Current density/Am-2
Electrochemical-thermal simulation
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
Electrolyte concentration
LiFePO4/C cell
398K
0 10000 20000 30000 40000 50000 60000 70000
420
450
480
510
540
Tem
pera
ture
rate
/K/s
Temperature Temperature rate
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
Temperature Temperature rate
Time/s
Tem
pera
ture
/K
0.00
0.01
0.02
0.03
0.04
0.05
Thermal simulation
Adiabatic
LiFePO4/Li-Ti-O cell
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
Electrode concentration Electrolyte
concentration
Oven test
0 2000 4000 6000 8000
300
350
400
450
500
Tem
pera
ture
rate
/K/s
Temperature Temperature rate
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
Positive Negative Electrolyte SEI Gasifing Solvent
Thermal simulation Oven test
Electrode concentration Electrolyte
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
Temperature Temperature rate
Time/s
Tem
pera
ture
/K
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Thermal simulation Oven test
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
Positive Negative Electrolyte SEI Gasifing Solvent
LiFePO4/C cell
468K
Thermal simulation Oven test
Electrode concentration Electrolyte
concentration
Temperature
LiFePO4/Li-Ti-O cell
468K
0 1500 3000 4500 6000 7500 9000
300
330
360
390
420
450
480
510
Tem
pera
ture
rate
/K/s
Temperature Temperature rate
Time/s
Tem
pera
ture
/K
-0.04
0.00
0.04
0.08
0.12
0.16
0.20
Thermal simulation Oven test
LiFePO4/Li-Ti-O cell
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
Thermal simulation Oven test
Electrode concentration Electrolyte
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
Electric current and temperature distribution on joint
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)
Electric current and temperature distribution on joint
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