Simulation and experiment of thermal energy management with phase change material for ageing LiFePO4 power battery

Thermal energy management performance of ageing commercial rectangular LiFePO4 power batteries using phase change material (PCM) and thermal behavior related to thermal conductivity between the PCM and the cell are discussed in this paper. The heat sources are simplified according to the experimental results of the cells discharged at 35 A (≈5 C). 3-D modules of a single cell and battery pack are formulated, respectively. The results show that the thermal resistance in the cell leads to an inevitable temperature difference. It is necessary to improve the thermal conductivity and to lower the melting point of the PCM for heat transfer enhancement. The PCM with a melting point lower than 45 °C will be more effective for heat dissipation, with a desired maximum temperature below 50 °C. The temperature difference in the whole unit before PCM melting will be decreased significantly. In addition, a proper kPCM:kc is necessary for a well designed battery thermal energy management system.

► We study the thermal energy management performance of ageing LiFePO4 power battery.
► 3-D modules of single cell and battery pack are formulated according to the experimental results.
► Thermal resistance in the battery cell leaded to an inevitable temperature difference.
► It is necessary to improve the thermal conductivity and lower the melting point of phase change material.
► Thermal conductivity of phase change material and battery exist an effective proportion.