Development and analysis of hybrid cooling concepts for an electric battery pack

In this paper, strategies and concepts are proposed to improve cooling and temperature uniformity within the battery pack. The proposed strategies are then analyzed through transient numerical studies. In particular, three different concepts were established. The first concept consisted of cooling through phase change material (PCM) only. The second concept was developed on the first concept by adding liquid channels that ran vertically through the PCM and were placed in between the cells. The third concept was further developed on the basis of the second concept. An air duct was added at the top of the battery pack, and the heat was extracted from the fluid within the liquid channel using the airflow. It is to be noted that the fluid within the second and third concepts is filled in the liquid channel and stays stationary. The results of the third concept indicated that the maximum temperature was maintained below 40 °C, the temperature uniformity was kept below 5 °C, and the lowest amount of PCM was utilized with a liquid conversion percentage of ∼6.1 %. This battery pack concept does not require excessive pumping fluid power and high air velocities, which implies that less energy is required for the operation of the thermal management system. This makes more energy available for propelling the vehicle.