Electrochemical-Thermal Simulation for Evaluating Indirect and Immersion Cooling in High-Power EV Charging

With the rapid advancement of electric vehicle (EV) fast charging technology, battery thermal management faces increasingly critical challenges due to elevated heat generation and stringent safety requirements. Conventional indirect cooling methods often struggle to provide sufficient heat removal under fast charging conditions, leading to potential safety risks. Immersion cooling has emerged as a promising solution because of its superior heat dissipation capability and uniform temperature distribution. In this study, an electrochemical-thermal coupled simulation framework is developed to evaluate indirect and immersion cooling performance under high-power charging conditions. A Pseudo-two-dimensional (P2D) electrochemical EV battery model is developed in GT-SUITE and validated against vehicle charging data. An immersion cooling system is also modeled and integrated into the battery framework to allow comparison with a conventional indirect cooling system under high-power DC fast charging scenarios. Simulation results indicate that immersion cooling achieves a maximum module temperature of 37.5 °C under 250 kW fast charge, which is 4 °C lower than the indirect cooling system. Furthermore, the immersion-cooled pouch cell battery pack can be charged from 10% to 80% SoC within 22 min, 11 min faster than using the indirect cooling system with a temperature limit of 42 °C. These findings demonstrate the potential of immersion cooling to enhance thermal safety, improve charging efficiency, and extend battery life in next-generation EVs.