Investigation on performance of composite phase change material based thermal management of electrical battery

The utilization of lithium-ion batteries in electric vehicles presents challenges due to the heat generated the during charging and discharging processes, leading to elevated operating temperatures and temperature differentials. These elevated temperatures adversely affect battery capacity, lifespan, and safety. To address this issue, an efficient battery thermal management system is essential to regulate battery temperature. In this study, the performance of composite phase change material (CPCM) based passive battery cooling system is investigated to improve the overall life of the battery. The CPCM is prepared using encapsulation methods using Graphene (1 wt%), Coconut oil (9 wt%) and Paraffin wax (90 wt%). The Graphene nanoparticle is added in CPCM to improve the thermal conductivity of pure PCM from 0.2 to 15 W/mK. Three distinct batteries with different cooling systems (conventional cooling, pure PCM-based cooling and CPCM based cooling) are developed using Lithium-ion 81,650 NMC battery cells in 7S4P configuration. The comparison of the thermal performance of the batteries during a discharging cycle is carried out at constant current 18.2 A. The results suggest that the CPCM based cooling system performed exceedingly well as compared to it’s counterpart—PCM based cooling system. Owing to better thermal conductivity of CPCM, a uniform temperature below 338 K is observed in CPCM based battery cooling system. Further, accumulation of heat (hot spot) near negative terminal of the battery with conventional cooling and PCM based cooling system is observed while no evidence of the hot spot in the CPCM based cooling system is found. The results obtained through numerical simulation corroborated the experimental results.