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. Immersion cooling has emerged as a promising solution because of its superior heat dissipation and uniform temperature distribution compared to conventional indirect cooling methods. This study develops an electro-thermal coupled simulation framework for evaluating indirect and immersion cooling performance under high-power charging conditions. A pseudo-two-dimensional (P2D) electrochemical battery model of an electric vehicle was developed in GT-Suite and validated against vehicle on-board charging data. In parallel, an immersion cooling system model was developed and validated using battery bench test results. This model was subsequently integrated into the vehicle model to allow comparisons with a conventional indirect cooling system under high-power DC fast-charging scenario. Simulation results indicate that immersion cooling achieves a maximum module temperature of 33.6 °C and a temperature gradient below 3 °C, significantly outperforming the indirect cooling approach. These findings demonstrate the potential of immersion cooling to enhance thermal safety, improve charging efficiency, and extend battery life in next-generation EVs.