Research on the heat dissipation performance of automotive Li-ion battery modules utilizing a combination of composite phase change materials and liquid cooling

Phase change materials, as a thermal management cooling method for batteries, have the problem of high-temperature heat dissipation failure under high rate operating conditions. This paper proposes a thermal management structure for battery modules that combines composite phase change materials (PCM) with liquid cooling to solve the heat dissipation limitations of passive cooling systems under extreme conditions. The specific structural design is analyzed and determined, and the system control strategy is optimized based on this structure. Firstly, the parameters of the liquid cooling system structure for the battery module are studied, which helps define the thermal management structure of the module. Then, the intervention conditions of the liquid cooling system are optimized to improve the utilization of the PCM. Finally, the heat dissipation performance of the thermal management structure under various configurations is evaluated. The results show that the setup of liquid cooling pipes and coolant can effectively reduce the temperature rise of the battery module. Compared to a system using only PCM, the temperature rise is reduced by 7 K. By adjusting the intervention time of the liquid cooling system, the utilization of PCM in the composite system is improved, with the liquid phase ratio of the PCM increasing by 35 %. In the optimized system, the module temperature can be controlled below 45 °C under 2C conditions, and the maximum liquid phase ratio of the PCM increases to 60 %. Under 3C conditions, the module temperature can be maintained within an appropriate operating range while ensuring the effective use of PCM.