Study of the effect of the aspect ratio of a cylindrical lithium-ion battery enclosure in an air-cooled thermal management system

Abstract

Batteries are utilized to store electrical energy in various devices due to their industrial importance, So in this paper, airflow is simulated in a channel to cool a two-dimensional, transient lithium-ion battery cylindrical cell. There is a circular PCM chamber around the battery. Battery cooling is evaluated by changing the aspect ratio of the PCM chamber and air velocity in the range of 0.2 to 0.4 and 0.001 to 0.005 m/s. COMSOL software is used for the simulations. The values of Tbattery, PCM chamber, the volume fraction (VFR) of molten PCM, and ambient air temperature are examined during the PCM charging and discharging process when the battery is working. The results of this study demonstrated that an enhancement in the air velocity causes the battery temperature (Tbattery), i.e., the maximum temperature and average temperature of the battery and the average temperature of PCM inside the chamber, to decrease. Also, the VFR of molten PCM is reduced with the air velocity. Over time, the values of air outlet temperature, Tbattery, and VFR of molten PCM decrease. Enhancing the aspect ratio intensifies the amount of temperature at the outlet. The aspect ratio of 0.2 corresponds to the lowest average temperature of the PCM chamber and the minimum VFR of molten PCM, while the aspect ratio of 0.35 corresponds to the highest average temperature of the PCM chamber and the maximum VFR of molten PCM.