Research on Thermal Management Coupling by CPCM and Liquid Cooling for Vehicle Lithium-Ion Batteries

This study addresses the issue of heat dissipation in 18,650 cylindrical lithium-ion battery packs and proposes a novel heat dissipation model that combines paraffin wax-expanded graphite composite phase change material (CPCM) with liquid cooling. Initially, a comparison is conducted between the heat dissipation effects of the battery pack under natural convection and the heat dissipation achieved through the utilization of CPCM. Subsequently, the CPCM model is employed to identify the optimal battery arrangement. Subsequently, a heat dissipation model is developed by coupling CPCM with liquid cooling. The simulation outcomes obtained using COMSOL software demonstrate that employing the paraffin-expanded graphite CPCM liquid cooling coupled heat dissipation model can achieve a reduction in battery spacing to 0 mm while maintaining the maximum surface temperature of the battery between 20–45 °C and improving the temperature uniformity of the battery during 1–3 C cyclic charging and discharging. This approach ensures the battery pack’s normal operation, enhances safety, and prolongs the battery pack’s service life.