Analyzing battery thermal management systems: A comparative study of hydrogel and various PCMs in different configurations and convection conditions

No comprehensive analysis has been conducted to compare the performance of hydrogel- and phase change materials (PCMs)-based approaches for cooling lithium-ion batteries in the literature. The present study addresses this gap by comparing the effectiveness of hydrogel and various PCMs in two pack configurations: a fully-filled pack (Pack I) and a partially-filled pack (Pack II) in different convection conditions. While PCM-filled packs show no significant decrease in the cell temperature as a function of the distance between the cells, hydrogel-based cooling results in a significant decrease of 5.27 °C in the maximum temperature of the pack (Tmax) with increasing the distance from the cell radius to twice the cell radius. The study also finds that the effectiveness of latent heat in reducing the cell temperature decreases at higher melting temperatures. Among Packs I with small cell distances, n-Octadecane with the melting temperature of 28°C performs best with Tmax of 45.1 °C at the end of the cycles. However, for large cell distances (twice the cell radius), the hydrogel pack outperforms other cooling methods with a Tmax of 36.1 °C. In Packs II, at all cell distances, n-Octadecane is preferred. For hydrogel, at the end of the cycles, Tmax of Pack I is 3.0°C lower than that of Pack II under natural convection conditions. The study also reveals that Packs II with forced convection conditions are more effective than Packs I. Finally, the research shows that dispersing graphene nano-plates in n-Octadecane has an insignificant effect on the thermal behavior of the battery packs.