A Review of Battery Thermal Management System for New Energy Vehicles at Subzero Temperatures

The pressure of energy transition and sustainable development has driven the rapid development of new energy vehicles (NEVs). Lithium-ion batteries (LIBs) are extensively utilized in NEVs because of their higher energy density, lower self-discharge rate, and environmental friendliness. Nevertheless, at subzero temperature environments, the electrochemical performance and available energy of LIBs are severely reduced, exhibiting significant charging difficulties, lifespan degradation, and safety issues. This performance degradation can contribute to the operational difficulties and safety hazards of NEVs. The purpose of this article is to provide a review of the challenges and limitations faced by LIBs in subzero temperature environments, as well as the development of subzero temperature LIBs from the cell level to the system level. Additionally, viable solutions to heat the battery by increasing the internal temperature are introduced. This paper provides a systematic review of low-temperature LIBs and offers a reference direction for the subzero-temperature thermal management of LIBs in NEVs.