Effect of Different Module Arrangements for Thermal Management of Cylindrical Li-ion Battery Packs

This study aims to analyze the effect of module arrangement in a lithium-ion battery pack using partial immersion cooling. The pack consists of sixteen modules with 192 cylindrical batteries in each module. The partial immersion method is used to reduce the total weight of the battery pack and thus increase the power density. Both pressure drop and temperature distribution are evaluated to find the optimum conditions of the cells and the pack. There is a trade-off between the pressure loss and the maximum temperature of the batteries. Moreover, the maximum cell-to-cell temperature difference between the cells is also evaluated as a new criterion for battery degradation in the pack. Different flow rates of the coolant which is a dielectric fluid are assessed to achieve the temperature target with the lowest pressure drop for various arrangements of the modules. The results show that during fast charging (15 kW), the 4S4P array (4 series 4 parallel) has the best performance compared with the other studies cases. Considering the temperature difference of 6°C for the coolant which results in the flow rate of 85 lpm, the total pressure drop is 0.18 bar in the pack with the average temperature of 33°C across the pack.