Experimental investigations of liquid immersion cooling for 18650 lithium-ion battery pack under fast charging conditions

•Liquid immersion cooling system as been proposed to cool a battery pack of 18,650 batteries.•The system has advantages in suppressing highest temperature and temperature non-uniformity.•The liquid immersion cooling consumes less energy than forced air cooling.•Effects of condenser flow rate and cooling water temperature were investigated for the system. In this study, a novel battery thermal management system (BTMS) based on FS49 is proposed and tested for cooling the cylindrical lithium-ion battery (LIB) module under fast charging conditions. Firstly, the temperature response of the battery module under 2 C and 3 C rates charging with forced air cooling (FAC) and liquid immersion cooling (LIC) is compared. The results indicate that the LIC has excellent heat dissipation performance, and the peak temperature of the module during 2 C and 3 C rates charging are reduced by 7.7 °C and 19.6 °C, respectively, compared with the FAC, while the corresponding cooling energy consumption of LIC is only 14.41% and 40.37% of the FAC. Meanwhile, the LIC embraces the advantages of minimizing the temperature non-uniformity in battery pack. The corresponding peak temperature difference of the module is just 1.1 °C and 1.2 °C, which is only 17.7% and 11.6% of that under FAC. Subsequently, the thermal management performance of the proposed LIC is investigated under conventional C rate discharging and different fast charging schemes. Finally, effect of condenser flow rate and cooling water temperature were investigated. This study demonstrates the application prospect of the LIC in the field of LIB fast charging.