A hybrid thermal management framework (PCM + VC + CP) for power batteries with large capacity

With the increasing demand for high-rate charging/discharging in electric vehicles, developing highly efficient thermal management strategies to ensure battery safety has become a critical necessity. This study proposed an integrated hybrid thermal management system incorporating phase change materials (PCM), ultra-thin vapor chambers (VC), and cold plate (CP). A comprehensive numerical simulation was performed to evaluate the thermal performances of three cooling plate layouts—bottom, middle, and side, under a severe 5C discharging condition. Results indicate that the side cooling plate scheme exhibits the optimal overall performance, yielding a maximum temperature of 42.61 °C and a maximum temperature difference of 15.67 °C, which are significantly lower than those of the other configurations. A parametric analysis reveals that the highly efficient synergy among the PCM, VC, and liquid cooling is uniquely achieved in the side arrangement. In contrast, heat dissipation in the middle and bottom schemes relies predominantly on liquid cooling, where the contributions of the PCM and VC are severely limited and constrained by axial heat accumulation induced by single-sided cooling. Furthermore, a sensitivity study demonstrates that increasing the PCM thickness from 0 mm to 6 mm effectively suppresses the temperature rise, whereas the performance gain saturates beyond 8 mm. Introducing a 0.4 mm-thick VC reduces maximum temperature and maximum temperature difference by 11.6% and 27.5%, respectively. Finally, varying the VC embedding depth within the 4–6 mm range exerts a marginal impact on the overall thermal resistance but manifests a mild optimal depth effect. The present work unveils the coupling mechanisms of three kinds schemes and provides a basis for developing more advanced hybrid battery thermal management systems.