Understanding the Effects of Cell Temperature Gradients on Battery Performance with Mathematical Modeling

Thursday, 1 June 2017: 14:30
Grand Salon C - Section 15 (Hilton New Orleans Riverside)
R. Deshpande, C. Shaffer, and W. Moore (Ford Motor Company)
With wide acceptance of lithium ion batteries for electric and hybrid vehicle applications, precise understanding of cell performance at different operating conditions is increasingly important. Cell temperature is often a critical variable determining the cell performance during the vehicle operation. For automotive applications, various cooling/heating strategies are used to keep the cell operating temperature within the predetermined limits. This ensures safety during cell operations as well as helps cells meet the cell warranty targets. Heat generation and heat rejection by a cell during the operation may result in non-uniform temperature distribution within a cell. These effects are pronounced in large format cells. The variation in local temperature affects the kinetic and transport rates and therefore, may result in non-uniformities in the current distribution across the length/breadth of the electrodes. Widely used, Pseudo 2D (P2D) porous electrode models may not be able to accurately predict cell performance with temperature distribution. Here a simple Pseudo 3D model is developed as an extension to the P2D model to understand the implications of the temperature gradient on the cell performance and eventually on the cell life. Differences in cell performance at uniform temperature operation and with cell temperature gradients are highlighted.