Numerical study on the effect of gallium filling on the cooling performance of battery thermal management system

Abstract

Fast charging and discharging scenarios necessitate battery thermal management systems with highly advanced and practical solutions. Using phase change material is a potential solution for battery thermal management. However, the finite thermal conductivity hinders application potential. Here, we suggest using a liquid-cooled plate as an auxiliary method and replacing a portion of the filled organic phase change material with metallic to create a two-stage battery thermal management system. In this study, the effect of the metallic phase change material’s filling ratio, the surrounding temperature, and the mass flow rate of the cooling liquid on the regulation of the cell temperature under the high-rate (9C) discharge condition is examined using numerical simulations. The results demonstrate that gallium filling significantly reduces cell temperature and improves temperature dispersion uniformity. When a quarter of the system is filled with gallium, the cell temperature drops below 40 °C, which is 2.43 °C lower than that is not filled. Gallium filling reduces the impact of ambient temperature. It is not advised that the coolant have a higher mass flow rate because this has less impact on the cell temperature and will increase the system’s energy consumption. Also, the temperature control effect is more pronounced at a high charge/discharge rate. In short, Gallium filling can increase phase change material’s thermal conductivity and improve the battery thermal management system’s cooling capacity.