Improving battery design with electro-thermal modeling

Operating temperature greatly affects the performance and life of batteries in electric and hybrid vehicles. Increased attention is necessary to battery thermal management. Electrochemical models and finite element analysis tools are available for predicting the thermal performance of batteries, but each has limitations. In this study we describe an electro-thermal finite element approach that predicts the thermal performance of a cell or module with realistic geometry. To illustrate the process, we simulated the thermal performance of two generations of Panasonic prismatic nickel-metal-hydride modules used in the Toyota Prius. The model showed why the new generation of Panasonic modules had better thermal performance. Thermal images from two battery modules under constant current discharge indicate that the model predicts the experimental trend reasonably well.