Thermal management of cylindrical battery pack based on a combination of silica gel composite phase change material and copper tube liquid cooling

Abstract

The lithium-ion battery(LIB) generates severe heat when discharging. In this study, a silica gel(SG) composite phase change material(CPCM) that is easy to fill was prepared, and its performance was tested, so as to ensure the safe operation of the battery. Besides, a battery cooling system combining CPCM and liquid cooling was established. Finally, simulation and experiment were performed to demonstrate the effectiveness of the battery pack cooling module. As revealed by analyzing the characterization results of the CPCM, the decomposition temperature of CPCM is more than 150 °C, the leakage rate of CPCM is less than 4 %, and the latent heat of phase change is 63 J/g. The thermal field simulation and discharge experiment of the battery module suggest that when the battery spacing changes from 5 mm to 15 mm and the thermal conductivity changes from 0.05 W/m·K to 0.75 W/m·K, the maximum temperature of the battery pack decreases by 10 °C, and the temperature difference between the batteries also decreases. When the flow of the variable displacement pump was maximum, the liquid cooling scheme of 3 inlets/3 outlets can still control the maximum temperature of the battery below 45 °C and make the battery temperature difference not exceed 2 °C, though the battery pack is subject to 3C(Discharge current rate) discharge - 1C(Charging current rate) charging cycle.