Experimental Exploration of Thermal Regulation in Li-ion Batteries Utilizing Liquid-Vapor Phase Transition in Direct Proximity to the Cells, in Combination with other BTMSs

In the present work, direct contact the refrigerant and the cells was employed for thermal management. This study experimentally investigates cooling the battery pack by allowing the refrigerant to directly contact the cells. Furthermore, it presents the first experimental evaluation of combining this approach with various active and passive cooling methods. According to the results, the cells’ maximum temperature decreased by 34°C at the end of the discharge. In the proposed system, the heatsink served as the only heat transfer path to the environment, where. heat transfer occurred via free convection. To enhance heat dissipation from the heatsink, the system was combined with active or passive Battery Thermal Management Systems (BTMSs). Using hydrogel between the fins of the heatsink decreased the cells’ maximum temperature by 0.5°C. However, the use of forced airflow between the fins of the heatsink did not affect the cells’ maximum temperature. The proposed system was also combined with an active forced liquid cooling system, and various water flow rates were investigated. At a flow rate of 200 LPH, the cells’ maximum temperature was reduced by 1.5°C compared to the mode without forced water flow. Additionally, different inlet water temperatures were examined, revealing that increasing the inlet water temperature leads to a significant rise in the cells' maximum temperature.