Thermal management challenges of li-ion battery packs using partial immersion cooling: analyzing pressure drop and temperature distribution

A partial immersion cooling system is used for cooling a battery pack equipped with cylindrical Li-ion batteries considering various flow rates of the coolant. The partial immersion method is used to reduce the total weight of the battery pack and thus increase the power density. A tiny gap of 2 mm is considered between the cells to have a high cell density. Both pressure drop and temperature distribution are evaluated to find the optimum conditions of the cells. Different flow rates of the coolant as well as heat generation rates of the cells are evaluated to achieve the temperature target with the lowest pressure drop. The results show that during fast charging (15 kW), considering the coolant flow rate of 21.5 lpm, the average temperature of 33°C can be achieved in the battery pack while the hot spot temperature is 51°C. While for the heat generation rate of 3kW, the average temperature of 33.8°C can be achieved using 2.15 lpm flow rate.