Liquid cooling system optimization for a cell‐to‐pack battery module under fast charging

Cell-to-pack (CTP) structure has been proposed for electric vehicles (EVs). However, massive heat will be generated under fast charging. To address the temperature control and thermal uniformity issues of CTP module under fast charging, experiments and computational fluid dynamics (CFD) analysis are carried out for a bottom liquid cooling plate based–CTP battery module. The impact of the channel height, channel width, coolant flow rate, and coolant temperature on the temperature and temperature difference are analyzed. A liquid cooling control method of exchanging the coolant inlet and outlet is proposed to optimize the temperature uniformity. Besides, the temperature uniformity enhancement by this control method at different intervals is compared. Results indicate that the flow rate and temperature positively affect the battery temperature; the maximum temperature can be reduced by 10.93% and 15.12%, respectively, under the same operations. However, the coolant temperature increment increases the maximum temperature difference by about 41.58%. Reversing flow enhances the cooling effect of conventional unidirectional flow of the CTP battery module under fast charging, especially for the thermal uniformity, which provides guidance for the battery thermal management system (BTMS) control under fast charging.