A Review of Thermal Management Technologies for New Energy Vehicles

Abstract

As new energy vehicles develop toward higher energy density, higher power output, ultra-fast charging, and operation over a wide temperature range, thermal management has become a critical factor affecting vehicle safety, service life, driving range, and overall vehicle efficiency. This paper systematically reviews thermal management technologies for traction batteries, motors, power electronic devices, cabins, and integrated vehicle systems. It first analyzes the major heat sources in new energy vehicles and their temperature effects; it then compares the heat-transfer characteristics, performance boundaries, and engineering applicability of air cooling, indirect liquid cooling, direct liquid cooling, phase change materials, heat pipes, and hybrid thermal management technologies; finally, it discusses motor and power electronics cooling, heat-pump air conditioning, waste-heat recovery, and multi-loop coupling. The comprehensive analysis indicates that indirect liquid cooling remains the mainstream approach for traction battery thermal management at present; direct liquid cooling and hybrid thermal management have considerable potential under high-rate and ultra-fast-charging conditions; and the focus of vehicle thermal management is shifting from local temperature control to multi-heat-source coordination and energy optimization. Future research should focus on breakthroughs in high-heat-flux fast charging, efficient low-temperature heating, suppression of thermal-runaway propagation, long-term reliability of advanced materials, and predictive control integrating models and data, while establishing a comprehensive evaluation system that considers safety, energy consumption, cost, and life-cycle impacts.