Spiral Cell Modeling with Battery Design Studio Robert Spotnitzmdx2.plm.automation.siemens.com/sites/default/files/Presentation/… · Battery Design LLC BDNTG Model 6 References

Battery Design LLC

Spiral Cell Modeling with

Battery Design Studio®

Robert Spotnitz

BD

Battery Design LLC

BD Battery Design LLC

Software for Battery Design and Simulation

2

Development started April 1999

Battery Design Studio®

the means to model batteries

•To analyze data

•To visualize cell designs

•To compare experiments with

models

•To visualize model results

•Database

InputModels

Output

Size

Cost

Power

Impedance

Life

Abuse, etcData

Lab

User

Battery Design LLC

BDCommon Cell Types

Pouch cell Prismatic cellRound cell

Battery Design LLC

BDCommon Cell Designs

Page 4

Negative

Post

Negative

Tabs

Positive

Tabs

Positive

Post

Package

sealant

layer

Negative

ElectrodePositive

Electrode

Separator

Pouch cell – every

electrode has a tab

For spiral

cells, how

many tabs

should be

used?

Where

should the

tabs be

spaced?

Battery Design LLC

BDCase Studies

Electrodes with 1 tab each

• Positive electrode tab position moves

• Negative electrode tab position at end of jellyroll by can

Effect of

• Cell size (18650, 26650, 36650)

• Electrochemical polarization

Using NTG model

5

Battery Design LLC

BDNTG Model

6

References

(1) J. Newman and W. Tiedemann, J. Electrochem. Soc. Vol. 140, No. 7,

July 1993 pp. 1961-1968.

(2) H. Gu, J. Electrochem. Soc., Vol. 130 No. 7 1983 pp. 1459-1464.

(3) U. S. Kim, Ch.B. Shin, C.-S. Kim, J. Power Src. 189 (2009) 841-846

dT

dUTVUAQ

DoDaDoDaDoDaadT

dU

DoDaDoDaaY

DoDaDoDaDoDaaU

A

IJ

Capacity

IdtDoDU

Y

JJDoDV

cell

cell

3

10

2

987

2

654

3

3

2

210

,,,

W ,generationHeat

Ke,Temperatur

A Current,

m area, Electrode

mS e,Conductanc

mA density,Current

V voltage,Equil.

(fraction) discharge of Depth

V voltage,cell Working

2

2

2

Q

T

I

A

Y

J

U

DoD

Vcell

Battery Design LLC

BDTab Positions

7

Tab Position

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Position of positive tab moves

Negative tab position is fixed at end

Battery Design LLC

BDSpiral Winder

Page 8

Battery Design LLC

BDCell Properties

Page 9

Value18650-p1 26650-p1 36650-p1

Active Area, m² 0.038 0.09 0.19

Active Coating Length, m 0.66 1.6 3.3

Capacity, Ahr 1.5 3.6 7.3

Energy Density, Whr/liter 327.0 374.3 402.5

Energy, Whr 5.4 12.9 26.6

Jellyroll Diameter, mm 17.6 25.5 35.5

Voltage, V 3.6 3.6 3.6

Volume, cm³ 16.5 34.5 66.1

Battery Design LLC

BDTab Positions (18650)

Page 10

0.5

0.4 0.3

0.60.8

0.1

Battery Design LLC

BD Case 1A – 20 A Discharges

11

Initial voltage drop depends on tab position

I

VOCVR

t sec1

Battery Design LLC

BDCell Resistance versus tab

position (Y=1000 S/m2)

Page 12

Battery Design LLC

BD18650 – Effect of Y

Page 13

Battery Design LLC

BD26650 – Effect of Y

Page 14

Battery Design LLC

BD18650 – LoY, Pos Plate

Voltage

Page 15

1

2

3

4

5

6

7

8

95.6 mV

62.8 mV

52.4 mV

44.4 mV

64.4 mV

41.0 mV

56.8 mV

67.3 mV

Battery Design LLC

BD18650 – LoY, Neg Plate

Voltage

Page 16

1

2

3

4

5

6

7

8

124.1 mV

124.5 mV

123.8 mV

123.9 mV

123.6 mV

92.9 mV

93.0 mV

92.9 mV

Battery Design LLC

BD18650 – LoY, Pos Inner

Current Density

Page 17

1

2

3

4

5

6

7

8

673 A/m2

660 A/m2

648 A/m2

639 A/m2

630 A/m2

611 A/m2

607 A/m2

604 A/m2

Battery Design LLC

BD18650 – LoY, Pos Outer

Current Density

Page 18

1

2

3

4

5

6

7

8 622 A/m2

626 A/m2

630 A/m2

655 A/m2

663 A/m2

672 A/m2

684 A/m2

698 A/m2

Battery Design LLC

BD18650 – LoY, Neg Plate Iin

Page 19

1

2

3

4

5

6

7

8 622 A/m2

698 A/m2

626 A/m2

630 A/m2

655 A/m2

663 A/m2

672 A/m2

684 A/m2

Battery Design LLC

BD18650 – LoY, Neg Plate Iout

Page 20

1

2

3

4

5

6

7

8

673 A/m2

613 A/m2

634 A/m2

640 A/m2

650 A/m2

663 A/m2

607 A/m2

608 A/m2

Battery Design LLC

BD26650 – LoY, Neg Plate

Inner Current Density

Page 21

1

2

3

4

5

6

7

8 297 A/m2

302 A/m2

311 A/m2

322 A/m2

335 A/m2

353 A/m2

374 A/m2

403 A/m2

Battery Design LLC

BD26650 – LoY, Neg Plate

Voltage

Page 22

1

2

3

4

5

6

7

8

161 mV

179 mV

176 mV

174 mV

167 mV

171 mV

165 mV

163 mV

Battery Design LLC

BD26650 – LoY, Pos Plate

Voltage

Page 23

1

2

3

4

5

6

7

8

192 mV

112 mV

91 mV

72 mV

60 mV

56 mV

78 mV

98 mV

Battery Design LLC

BD26650 – HiY, Pos Plate

Voltage

Page 24

1

2

3

4

5

6

7

8

133 mV

117 mV

102 mV

86 mV

55 mV

71 mV

43 mV

48 mV

Battery Design LLC

BD36650 (LoY) Plate Voltage

Page 25

Pos-1 Pos-8

Neg-1 Neg-8

146 mV

220 mV

218 mV

322 mV

Battery Design LLC

BD36650 (LoY) Iin

Page 26

Pos-1 Pos-8

Neg-1 Neg-8

308 A/m2

344 A/m2

180 A/m2

217 A/m2

Battery Design LLC

BDCircuit Model – Same end tabs

Negative

Positive

Placing tabs at same ends gives most non-uniform

current distribution, but minimizes measured voltage

drop in collectors

Echem

current

Battery Design LLC

BDCircuit Model – Opposite tabs

Negative

Positive

Placing tabs at opposite ends gives most uniform

current distribution, but maximizes measured

voltage drop in collectors

Battery Design LLC

BDCircuit Model – center tab

Negative

Positive

Placing tabs at center trades off voltage drop in collectors

and current flow through cell

Battery Design LLC

BD Summary

Optimum position of tab along the current collector depends on resistance of collectors and electrochemical resistance• Low ratio of Rechem/Rcoll favors placing tabs on

same ends, while high value favors placing tabs on opposite ends

Simulation capability for electrical distribution in spirally-wound cells developed. This tool enables simulation studies to determine optimal position of tabs and dimensions of current collectors

30

Battery Design LLC

BD Summary

Optimum position of tab along the current collector depends on resistance of collectors and electrochemical resistance• Low ratio of Rechem/Rcoll [(1/YA) / (L/A)] favors

placing tabs on same ends, while high value favors placing tabs on opposite ends

Simulation capability for electrical distribution in spirally-wound cells developed. This tool enables simulation studies to determine optimal position of tabs and dimensions of current collectors

31

Battery Design LLC

BD

BACKUP

32

Battery Design LLC

BDMultiple Tabs

Page 33

Battery Design LLC

BD26650 (LoY) Plate Voltage

Page 34

Pos-1 Pos-8

Neg-1 Neg-8

Battery Design LLC

BD26650 – HiY, Pos Plate Inner

Current Density

Page 35

1

2

3

4

5

6

7

8

133 mV

117 mV

102 mV

86 mV

55 mV

71 mV

43 mV

48 mV

Battery Design LLC

BD26650 (LoY) Iin

Page 36

Pos-1 Pos-8

Neg-1 Neg-8

Battery Design LLC

BD26650 (LoY) Iout

Page 37

Pos-1 Pos-8

Neg-1 Neg-8