Experimental study on thermal behavior of PCM-module coupled with various cooling strategies under different temperatures and protocols

Phase change materials (PCMs) are widely used in battery thermal management system (BTMS). Most previous research on BTMS has focused on single temperature environment or protocol, without verifying their effectiveness in volatile working environments, which affects battery heat accumulation and dissipation. In this study, a series of experiments is first conducted to compare the thermal behaviors of battery thermal management modules with different protocols and ambient temperatures to determine the applicability of PCM cooling strategies in different operating conditions. The results show that the constant-current mode produces a smaller temperature fluctuation range but higher temperature, which weakens the effect of PCM cooling and accelerates its failure, especially in high-temperature environments. The PCM cooling technology fails at 1518 s at 54.0 °C in the 45 °C environment with constant current mode while it fails at 2969 s at 44.1 °C in the 35 °C environment. On this basis, we propose a novel PCM cooling structure coupling copper-plate-enhanced heat pipe with PCM to improve secondary heat dissipation, whose cooling performances are compared between forced convection and natural convection. These outcomes can provide a new reference and more insights into diverse application conditions and environments.