battery design studio update - mdxmdx2.plm.automation.siemens.com/sites/default/...(2) battery...

Advanced Thermal Modeling of Batteries

CBD Battery Design LLC

Battery Design Studio

Update March 20, 2012 13:30 – 13:55

http://www.cd-adapco.com/

New Features Covered Today

• 3D models

• Voltage dependent diffusion

Let’s start with brief introduction to Battery Design Studio®

Battery Design LLC CBD

Battery Design Studio®

A user-friendly interface between battery designers and users for costing, sizing, and correlation of test data to performance, safety, and life predictions.

Development started APR1999 interface

Input Model Output

Size

Cost

Power

Impedance

Life

Abuse, etc Data

Lab

User

Battery Design LLC CBD Standardized software promotes

(enables) communication

Models Input

Output Materials Supplier

Input

Output

Battery Developer

Exchange of battery information.

Modeler

Input Output Input Output

Modeler

CBD

Battery Design Studio®

Formulations Cell Design Test conditions

Standardization lowers cost, allows faster product introduction.


BDS Cell Design Process

Physical Cell Description

• Coin, cylindrical pouch, prismatic

•Gives size, weight, equilibrium voltage, capacity, bill of materials, etc.

Fit Model Parameters

• circuit, physics

• Allows simulation of performance

Use and/or Distribute

Text Battery Model (TBM)


TBM files bridge the

supply chain of batteries

•Button cell

•Formulations

•Test results

Materials Developer (cathode, anode,

separator, electrolyte, etc.)

•Model selection

•Electrodes, incl. tabbing

•Separator

•Cylindrical, prismatic, pouch

Cell Designer •Performance estimation

•Model selection

•Series/Parallel cells

•Cooling

End User, Module and/or Pack Developer

TBM file, prg, out

TBM file

STAR-CCM+


3D MODEL THEORY


Unit Cell Concept

Material between current collectors represented as unit cell.

Collectors modeled as resistors connecting unit cells.

Negative current collector

Positive current collector

Unit Cell

Battery Design LLC CBD Selected Simulation Models in

Battery Design Studio ®

2654

3

3

2

210

DODaDODaaY

DODaDODaDODaaU

UVVYJ np

(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

(1) T. Fuller, M. Doyle, J. Newman, J.

Electrochem. Soc. 141 (1994) 1-10

(2) Battery Design LLC, “BDS

Documentation”

M. Verbrugge and R. Conell, J.

Electrochem. Soc. 149 (2002) A45-A53

Cell Design

DISTNP

HEV/PHEV Module/Pack

RCR

EV Module/Pack

NTG

Solves transport, kinetics, equations

Quick response for frequent charge/ discharge like HEV/PHEV energy storage

Simple, easy to create model , and best for simple discharging thermal analysis


3D CELL DESIGNS


Stacked Plate Design


Spirally Wound Design


18650 – LoY, Pos Plate

Voltage

1

2

3

4

5

6

7

8


18650 – LoY, Pos Inner

Current Density

1

2

3

4

5

6

7

8


18650 – LoY, Outer Current

Density

1

2

3

4

5

6

7

8


18650 – LoY, Neg Plate

Voltage

1

2

3

4

5

6

7

8


18650 – LoY, Neg Plate Iin

1

2

3

4

5

6

7

8


18650 – LoY, Neg Plate Iout

1

2

3

4

5

6

7

8

CONCENTRATION-DEPENDENT DIFFUSION COEFFICIENTS

Concentration-dependent diffusion coefficients

• Solid-phase diffusion coefficients are known to depend on concentration.

• Theory shows that diffusion coefficient depends on derivative of equilibrium potential (E) with respect to lithium fraction (x).

Concentration dependence of lithium diffusion coefficient in LiCoO2, Young-Il Jang, Bernd J. Neudecker, and Nancy J. Dudney, Electrochemical and Solid-State Letters, 4 (6) A74-A77 (2001)

dx

dE

RT

FxD

xd

adDD LiLiLi

ln

ln~

• Correction can be significant.

• BDS accounts for this correction.

Accounting for concentration dependence of solid-phase diffusion coefficients in BDS (1)

Use “Monotonic cubic” mode for interpolation of voltage data.

Accounting for concentration dependence of solid-phase diffusion coefficients in BDS (2)

Just check option for “Diffusion Conc. Correction”

Example: NCM/Graphite Cell

NCM Equilibrium Curve Graphite Equilibrium Curve

dx

dE

E

x

x Cathode material shows significant effect of voltage on solid-phase diffusion coefficient.

Simulation Results: Discharge Curves

Effect of variability in solid-phase diffusion coefficient becomes more significant at higher rates.

~40 mV delta ~2.5% capacity delta



Simulation Results: Diffusion Coefficient Variation across cell for 3C Discharge

Constant Diffusion Coefficient Variable Diffusion Coefficient

Distance from negative collector, mm

Time, min

Solid-phase diffusion coefficient has complex profile when concentration dependence is accounted for.

Simulation Results: Solid-Phase Concentration Variation across cell for 3C Discharge

Constant Diffusion Coefficient

Variable Diffusion Coefficient

Distance from negative collector, mm

Variable diffusion case results gives smaller concentration gradient in positive electrode.

Negative Positive

Surface concentration

Average concentration

Summary

• Dependence of solid-phase diffusion coefficient with lithium concentration has a strong theoretical foundation, and experimental validation.

• Accounting for concentration dependence of solid-phase diffusion coefficients has a significant effect of cell behavior at high rates.

• BDS allows this effect to be simulated with ease.


Conclusion

Battery Design Studio® is the industry standard platform for:

• Analyzing data and visualizing results.

• Exchanging battery data and models.

• Pathway to pack and system design

with STAR-CCM+.

battery design studio update - mdxmdx2.plm.automation.siemens.com/sites/default/...(2) battery...

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