Thermal Behavior of a Cylindrical 18650 LiFePO4 Battery during Charge and Discharge Cycles

A two-dimensional electro-thermal model is used to predict the thermal behavior of a cylindrical 18650 LiFePO4 battery during charge and discharge cycles. Under a forced convection, current rate and convective heat transfer rate on the surface of the lithium-ion battery are varied to analyze the temperature distributions in the battery. After several charge and discharge cycles, the battery achieves a steady-state with a constant temperature range. The maximum temperature in the battery increases with the increase in the current rate that enhances the heat generation, whereas the increasing convective heat transfer rate reduces the temperature of the battery by dissipating the heat to the surroundings. The thermal behavior shows that the LiFePO4 battery should be operated under forced convection conditions with a convective heat transfer rate of at least 10 W/m2K for safe battery driving.