Thermal performance investigation of an air-cooled lithium-ion battery pack considering the inconsistency of battery cells

Abstract

A lithium-ion battery pack is the power source of an electric vehicle, and its temperature rise is one of the main concerns. Existing research mainly focused on the design of cooling systems, and always used computational fluid dynamics to analyze the thermal behavior of batteries, regardless of the individual differences of batteries. In this paper, the heat dissipation performance of air-cooled battery packs considering the different thermal performance of different batteries was studied. A more realistic thermal model of the battery pack at 1C discharge rate was obtained through equivalent calculation and experimental verification. The results showed that the temperature of batteries with different thermal performance rose faster and the temperature difference was larger. At the same time, the thermal performance of the battery can be improved by placing the outlet and inlet on the same side. The thermal performance was more sensitive to the inlet exhaust height than to the outlet exhaust height. The research results can provide a basis for exploring the design method of battery packs with better heat dissipation performance, lower energy consumption, and a smaller volume.