Thermal management of a LiFePO4 battery pack at high temperature environment using a composite of phase change materials and aluminum wire mesh plates

One of the most significant factors affecting the performance and life cycle of lithium-ion batteries is temperature. During the charging and discharging processes a large amount of heat is continuously generated inside the cells causing an increase in surface temperature which results life time deterioration to the pack's performance and power supply and in severe conditions causing an explosion inside the car especially in the hot temperature regions. In this study a composite of a phase change material and aluminum wire mesh plates has been used for the thermal management system of LiFePO4 pack to control the temperature rise of the batteries at high temperature regions (50-55 °C). Poly Ethylene Glycol 1000 (PEG1000) with melting point of 35-40 °C has been used as a phase change material. Aluminum wire mesh plates have been applied to the PCM for thermal conductivity enhancement and also to improve the temperature uniformity of the system. Preliminary experimental runs have been performed in charge and discharge of the batteries at different rates of 1-3 C to obtain the maximum surface temperature of the cells. Due to the page limit of the manuscript, only the discharge results are presented here. A mathematical model has been developed for one of the cells in COMSOL ver. 5.1 and the results of the model have been verified by the experimental data obtained at different conditions. The results show that using the PCM and aluminum wire mesh plates between the cells can reduce the surface temperature significantly and causes better performance for the battery pack. The maximum cell surface temperatures at ambient temperature condition have been reduced by 19%, 21%, and 26% for the rates of 1 C, 2 C, and 3 C respectively.