Effect of mechanical vibration on phase change material based thermal management system for a cylindrical lithium-ion battery at high ambient temperature and high discharge rate

The performance and safety of lithium-ion batteries (LIB) in electric vehicles (EV) depend strongly on the operating temperature, so an effective battery thermal management system (BTMS) is essential. Battery thermal management (BTM) technology based on phase change material (PCM) is currently considered to be one of the most promising approaches. Electric vehicles are inevitably affected by vibration during operation, and many studies have shown that mechanical vibration can enhance natural convection heat transfer. The effect of mechanical vibration on the PCM-based battery thermal management module of a single cylindrical lithium-ion battery at high ambient temperature and high discharge rate is studied by numerical simulation for the first time in this paper. N-octadecane is selected as the PCM application in the cylindrical battery's periphery. The results show that: (1) mechanical vibration enhances the heat transfer of natural convection to limit the excessive temperature rise and improve temperature uniformity of the lithium-ion battery, and when the PCM is 12 mm, the mechanical vibration has the most significant impact on the PCM-based BTMS (2) when the vibration frequency is 10 Hz, the cooling effect of the battery thermal management module is the best, which is 28.05% lower than when there is no vibration. when the vibration frequency is 50 Hz, the temperature uniformity of the battery is the best, with a maximum temperature difference of 3.86 K. (3) when the vibration amplitude is 100 mm, the maximum temperature difference of the battery is 1.89 K, and the maximum temperature decreases by 27.74%. This study provides a new perspective for the thermal management system of lithium-ion batteries for electric vehicles.