Analysis of the thermal behavior of a LiFePO4 battery cell

This paper presents theory, experiments and numerical modeling results for the electrothermal analysis of Lithium Iron Phosphate (LiFePO4) battery cells. Thermal management of batteries is important for several reasons including thermal runaway and maintaining battery operating time. A battery pack is comprised of battery cells which are stacked together without cooling surfaces except for the pack outer surface. The central cells in the pack are therefore exposed to the risk of overheating. A model for a single specific commercial LiFePO4 battery cell is presented together with preliminary experiments and results for determination of heating sources during charging and discharging. Based on the experimental results we extract model parameters for use in the model. The experiments lead to relations for the cell surface temperature and the lump temperature of the cell. A reasonable agreement between experiments and the model is found and suggestions for further work is indicated.