Electro-Thermal Analysis of Lithium Ion Batteries: Experimental and Numerical Study

Gad Pinhasi, Department of Chemical Engineering , Ariel University of Samaria, Ariel, Israel

Battery management is essential for achieving desired performance and life cycle from a particular battery pack in Electric and Hybrid Vehicles (EV and HEV). A proper understanding of heat generation and design of heat dissipation paths are critical for ensuring the safety of lithium ion modules.

This work reports the laboratory test and numerical results of a Li-ion battery designed for electric vehicle applications. In the experimental part, batch and flow calorimeters were used to measure the heat generation from cells and batteries for different load characteristics. The temperature was also measured in different points in the batteries. For each battery type, the heat generation rate depends on the initial state of charge, initial temperature, and charge/discharge profile.

In the theoretical part, a finite difference model was built and was used in a finite element analysis software (COMSOL Multiphysics) to perform thermal analysis of single cell and battery. The thermal-electrochemical model is multidimensional and capable of predicting the average cell temperature as well as the temperature distribution inside a cell.

Using the developed models the engineer can improve thermal design by reducing resistances, improve power capability of batteries, and avoid extreme hot spots in cells that lead to premature aging of cells.