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 (approximate to 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 degrees C will be more effective for heat dissipation, with a desired maximum temperature below 50 degrees C. The temperature difference in the whole unit before PCM melting will be decreased significantly. In addition, a proper k(PCM):k(c) is necessary for a well designed battery thermal energy management system. (C) 2011 Elsevier Ltd. All rights reserved.