1. Correlation Between Heat Production and Strain in Lithium-Ion Battery Separator Layers
Daniel Bautista, Alex Francis, Mason Pingel, Michael Powley and Dr. Ilya Avdeev

2. Motivation
2013 Tesla Model S
2011 Chevy Volt

3. Motivation
2013 Tesla Model S
2011 Chevy Volt

4. Design of a battery pack with predictable response to crash
Motivation
Design of a battery pack with predictable response to crash

5. Previous Research Cross section Surface view Before compression
After compression

6. 100 6P Li-Ion Battery Separators Sample

7. Compression Test Setup

8. Compression Test Methods
Four different samples of 100 layers of Li-Ion separator layers.
Loaded at four different load levels
Yield
45,000N
30,000N
15,000N

9. Load vs Extension Results
Sample 1 -- Yield
Sample 2 – 45,000N
Sample 3 – 30,000N
Sample 4 – 15,000N

10. Combined Stress-Strain Results

11. Determining Change in Resistance
𝑅= 𝑅 𝑒 𝜏𝑙 Φ𝐴
∆𝑅= 𝑅 −𝜀 𝛼 −𝜀/ Φ 0 𝛼 −1
𝜏= Φ 1−𝛼
Cathode R R R R R
Anode

12. Resistance Scenerios
Three main cases that can take place at different parts of the impacted cell.

13. Objectives Pack Level Cell Level Laminate Level Explicit dynamic FEA
Parametric design
Multiphysics
Enclosure design
Cooling
Cell design
Jelly-roll vs. pouch
Connectors
Stresses/strains
Energy balance
Electric shorts

14. Impact Test Setup Drop cart weight Custom designed drop-test apparatus
Height: 2.8 m
Impact velocity: 7.4 m/s
Impact tests:
Lateral test
Lateral using rigid bar
Axial test
Drop cart weight
11.34 and Kg

15. Layered Model

16. Cell/Unit model progress
Thermal Solution
Mechanical Loads
Electric Load History
Electro-Chemical Model
Thermo-Mechanical Model
Strain
Stress
Temp.
Current
Output Solution File
Sequential Incremental
Coupling

17. Thermal Model Review: Heat generation models Thermal properties
Deformed cell model development
Thermal simulation: transient charge

18. Irregular Temperature Distribution
Time
30 s
145 s

19. References
Gilaki, M., & Avdeev, I. (2016). Impact modeling of cylindrical lithium-ion battery cells: a heterogeneous approach. Journal of Power Sources, 328,
Gilaki, Mehdi, Alex Francis, Daniel Bautista, and Ilya Avdeev. "Progress Toward Understanding Catastrophic Failure of Electric Vehicle Li-Ion Batteries: Multi-Physics Modeling."Volume 14: Emerging Technologies; Materials: Genetics to Structures; Safety Engineering and Risk Analysis (2016): n. pag. Web.
J. Cannarella, C. B. Arnold, Ion transport restriction in mechanically strained separator membranes, Journal of Power Sources 226 (2013)