Abstract
The objective of this thesis was to determine the ideal cooling method for lithium-ion batteries used by electric vehicles. Internal heat generated within the battery pack during charging and discharging must be accommodated with proper thermal management. The battery must maintain operating temperatures between 25°C and 40°C to provide maximum power output and performance. Theoretical calculations for air, fin, and liquid cooling method were performed to determine the heat rate values based on a battery pack sized 500x300x200 mm. ANSYS software was used to perform simulations and to validate calculations. Meshing of the geometry was done and internal heat generation and convection were applied to the model of the battery pack. Results were compared for total heat flux and temperature. Air cooling method had a maximum total heat flux of 24,445 W/m2 and maximum temperature of 48.8°C. Fin cooling method had a maximum total heat flux of 9,223.4 W/m2 and maximum temperature of 35.116°C. Liquid cooling method had a maximum total heat flux of 10,465 W/m2 and maximum temperature of 34.098°C. Based on these results, the lowest maximum temperature provided was by the liquid cooling method. Furthermore, a modified battery pack was designed with additional air outlets to enhance the convection process of the air cooling method. Simulations on ANSYS software determined the modified battery pack to be most efficient in thermal management with a maximum temperature value of 32.526°C.