Investigation of the thermal performance of axial-flow air cooling for the lithium-ion battery pack

This paper presents an investigation of the thermal performance of axial flow air cooling for lithium-ion battery pack. A thermal model for a battery pack with 32 single cells is developed and is numerically solved with coupling the fluid governing equations. The heat generation rate of the battery is calculated by a UDF (user defined function) program, which is based on a pseudo 2D model of the lithium-ion batteries. The effects of the radial interval between cells and air flux on the thermal performance of the axial flow air cooling system are investigated by numerical simulations. The results show that increasing the radial interval leads to a slight average temperature rise but benefits to the temperature uniformity of the battery pack. A larger radial interval can significantly reduce the power cost of the cooling system; however it causes a decrease of space efficiency mildly. A larger air flux is found to be benefit to the temperature uniformity within battery pack. An optimal region based on the assessment of the power cost, space efficiency and temperature homogeneity for the parameter designs of the battery cooling system is presented.