Synergy analysis on the heat dissipation performance of a battery pack under air cooling

Li-ion batteries are widely used for battery electric vehicles (BEV) and hybrid electric vehicles (HEV) due to their high energy and power density. A battery thermal management system is crucial to improve the performance, lifetime, and safety of Li-ion batteries. The research on the heat dissipation performance of the battery pack is the current research hotspot in the electric vehicle industry. In this paper, battery modules and battery pack are simplified to heat source and semi-closed chamber, respectively. The field synergy principle and CFD technology were used to make a synergy analysis on its heat dissipation performance. Thermal flow fields of different air outlet modes were considered in this paper, and the results show that the heat dissipation performance of air-cooled battery pack increases with the improvement of the synergy degree between velocity field and temperature gradient field. Compared with other air outlet modes, the upper air outlet mode has the best cooling effect, when the inlet air flow rate is 0.444 m/s, the maximum temperature rise and the maximum temperature difference of heat source can be controlled at 7.01 °C and 3.08 °C.