Experimental and numerical study of lithium-ion battery thermal management system using composite phase change material and liquid cooling

An efficient battery thermal management system can effectively control the temperature of the battery and prevent the occurrence of thermal runaway. In this work, the calibration calorimetry method is first used to determine the specific heat capacity and heat generation rate of a large-capacity battery considering the heat loss. Then three cases of large-capacities battery thermal management systems (BTMSs) are proposed, i.e., Case 1 with composite phase change material (CPCM) cooling only, Case 2 with liquid cooling only, and the hybrid Case 3 combined CPCM with liquid cooling. It is found that Case 3 owns the lowest maximum temperature of the battery module under the same condition. Moreover, the parameters affecting the thermal performance of Case 3 are studied, including the thickness of CPCM, inlet velocity of coolant, ambient temperature and discharge rate. A thickness of 4 mm for CPCM can effectively absorb the heat released by the batteries to achieve higher group efficiency of the battery module and lighter weight of the system. The lower velocity of 0.1 m/s is preferred in the simulation to balance the maximum temperature and pump power consumption. Moreover, Case 3 is well verified to control the maximum temperature and temperature difference of the battery module at 48.97 °C and 4.5 °C, respectively, even under the highest discharge rate of 2C and high ambient temperature of 37 °C, which shows effective improvement in the thermal safety of batteries.