Design and thermal analysis of Fin-PCM-integrated thermal management system for lithium-ion cylindrical battery pack

A fin and phase-change material (PCM) integrated battery thermal management system (BTMS) for the 18650 cylindrical Li-ion battery is designed, analysed, and validated with experimental results. The performance of different cooling techniques such as natural air convection cooling, fin cooling, PCM cooling, and fin-PCM cooling is investigated for a single battery and a 14S1P battery pack and compared. A PCM-based BTMS is employed to absorb the heat from the battery, thereby lowering its temperature and maintaining its temperature uniformity. N-eicosane is used as a PCM for this study. It has a melting temperature of 308 K. Result shows at a 5C discharge rate. The PCM cooling system lowers the temperature by approximately 31 K, and the fin-PCM system lowers the battery temperature by 33 K compared to simple natural air convection cooling. The experimental results agree with the numerical simulations with an error below 1%. The results show that connecting batteries in series does not affect the heat generation and battery surface temperature.