Effects of air cooling structure on cooling performance enhancement of prismatic lithium-ion battery packs based on coupled electrochemical-thermal model

Abstract

The increasing temperature of lithium-ion batteries during charging and discharging affects its operational performance. The current studies mainly adopt simplified model, less considering the effect of the battery internal electrochemical reaction on the air cooling performance, and the air cooling structure needs to be further optimized. In order to solve the problems above, the coupled electrochemical-thermal air cooling model was established, and the air cooling structure was optimized in terms of the relative position and height of the battery pack inlet and outlet, the distribution, and spacing of cells. The results show the better air cooling performance is achieved when the inlet and outlet are aligned on the same side. When the lateral inlet and outlet aligned on the same side, the lower outlet height is more important for improving the heat dissipation performance of the battery pack, but the worse temperature uniformity emerges. According to the cooling performance of different positions in the battery pack, a method for nonequidistant symmetrical distribution of cells is able to improve the temperature uniformity. The optimal combination of the air cooling structure with various factors is obtained.