Study of circular, horizontal and vertical elliptical enclosures filled with phase change material in thermal management of lithium-ion batteries in an air-cooled system

In this paper, the battery cooling is examined by placing a battery cooling system in the airflow path. The cooling system consists of 9 cylindrical battery cells so that a phase change material (PCM) surrounds them. PCM is housed in horizontal and vertical elliptical (ELL) and circular enclosures. The amount of PCM used in enclosures is equal and the effect of enclosure shapes on battery temperature (T_Bat) and the rate of phase change of PCM is evaluated. COMSOL software is employed to simulate the battery cooling system. The results demonstrate that the use of PCM enclosures with vertical ELL shape causes the highest maximum temperature (T_max-b) and the average temperature (T_av-b) of battery cells, while horizontal ELL ones produce the lowest T_max-b and the T_av-b. The maximum amount of liquid PCM at different times corresponds to vertical ELL enclosures and the minimum amount of average volume fraction of PCM is related to horizontal ELL enclosures. Utilizing the enclosures with horizontal ELL shapes creates the minimum outlet air temperature. The circular ones have the maximum outlet air temperature.