A numerical study of enhanced lithium-ion battery cooling using a module insert

Abstract

Thermal performance of an electric vehicle (EV) battery module with an integrated cooling insert was numerically analyzed using computational fluid dynamics (CFD). Twelve NCM prismatic cells were packaged into a module where each cell was physically isolated from its neighboring cells by the cooling insert, designed to enhance the module's thermal performance. The battery cells and the cooling insert were attached to a thermal interface material (TIM) and a cooling plate with integrated liquid cooling where the coolant was a 50/50 ethylene glycol water (EGW) mixture. A heat generation model based on the discharge rate was used to assess the thermal responses of the module such as heat flux and temperature distribution. Thermal characteristics were studied under various discharge rates, coolant flow rates, insert thicknesses and material conditions. Results showed that the cooling insert reduced the cell temperature by 1.4 degrees C and increase the heat flux by 15.6% at 3 mm thickness with a coolant flow rate of 4 L/min. Cooling plates with plastic and metallic material properties were also studied and temperatures reductions up to 0.7 and 1.0 degrees C were observed, respectively. Furthermore, temperature uniformity was maintained to within 0.3 degrees C across all twelve cells at a coolant flow rate of 9 L/min. The results of this study could potentially lead to the development of a compact and low-cost intra-cell heat spreader in a battery module that can be readily implemented in production EVs.