Thermal analysis of modified Z-shaped air-cooled battery thermal management system for electric vehicles

The development of new energy vehicles (NEVs) is an effective measure to cope with climate change and mitigate the exhaustion of non-renewable energy sources. Lithium ion power battery is crucial to the reliability and safety of NEVs. In this paper, we design a modified z-shaped air cooling system with non-vertical structure, and study the thermal behavior of lithium iron phosphate power battery. The new system tilts the arrangement of battery packs according to different angles, thus forming a non-vertical flow channel structure. Compared with the traditional Z-shaped air cooling system, the maximum temperature of the battery pack is reduced from the initial 38.15 °C to 34.14 °C with a decrease of 10.5 %, and the temperature difference is reduced from the initial 2.59 °C to 1.97 °C with a decrease of 23.9 %. The modified air-cooled battery thermal management system speeds up the heat exchange rate between the air and the battery pack, which is beneficial to improve the cooling performance and temperature uniformity. This study propose a foundation design of the modified z-shaped air cooling system to improve the safety of electric vehicles, which has certain engineering value for the further development of BTMS. •The modified z-shaped air cooling system with non-vertical structure is first proposed for BTMS.•The non-vertical structure design is suggested to enhance the cooling performance.•Parameters are devised to evaluate the structural designs for the battery pack.