Thermal performance enhancement of a passive battery thermal management system based on phase change material using cold air passageways for lithium batteries

The hybrid battery thermal management system (BTMS), the combination of an active thermal management system (TMS) and a passive TMS based on phase change material (PCM) will keep the battery temperature within a suitable range while possessing a greater cooling effect in comparison with a passive TMS and using less energy than an active TMS. Throughout this research, the structure role of the active TMS that comprises an air cooling system is investigated. To this end, nine case studies possessing three different cooling duct structures and three different cold air stream pressure differences are simulated and studied. The outcomes indicate that the rising of the temperature, even for the worst-case scenario, is safe, acceptable, and smooth-enough for thermal management considerations. The maximum temperature of the cells never exceeded 314 K, showing the perfect capability of proposed hybrid BTMS. Furthermore, one can notice that the more powerful the inlet air stream or the more length of cooling ducts through the PCM volume, the lower battery surface temperature is experienced. Additionally, in all simulated cases, the maximum temperature difference of the cells within the battery module does not go beyond 1.6 °C, demonstrating the excellent aptitude of proposed hybrid BTMS in creating uniform temperature distribution within the battery pack. On the other hand, it is concluded that the more powerful the inlet air stream gets or the more length of cooling ducts through the PCM volume is applied, the larger maximum temperature gradient is observed.