A Study on the Estimation of Air Flow Rate with Discharge Sate for an Air-cooled lithium-ion Battery Pack Using CFD Simulation

The battery thermal management system(BTMS) is essential in the performance and long lifespan of lithium-ion battery packs used in electric vehicles(EVs). In the present work, the cooling performance of an air-cooled battery pack was investigated by estimating appropriate air flow rate for various C-rates. This study sought to provide a basic strategy to enable optimized cooling for an air-cooled battery pack. For this purpose, the heat flux of an NCR18650B cylindrical battery was obtained using the electro-thermal model. CFD simulations were subsequently conducted for the battery pack The appropriate air flow rate for maintaining the battery temperature at 25-40 °C was evaluated in terms of maximum(average) cell temperatures and difference between two temperatures. Results show that with increasing C-rate, the suitable range of air flow rate increases for optimized cooling. It is expected that the data from this study can effectively contribute to the setup of robust air-cooled BTMS.