A Review of Liquid Cooling for Electric Vehicle Thermal Management

Abstract

As global automotive industries undergo a massive transition toward New Energy Vehicles (NEVs), maintaining the suitable temperature for the increasing compact and high- power electric motors has become a significant challenge. This review of literature systematically reviews the history, current state, and future path of development of liquid cooling technologies for electric vehicle (EV) thermal management. By comparing traditional air cooling with advanced liquid cooling — including the innovative application of hybrid nanofluids, direct liquid cooling, and micro pump integration— this review highlights the thermal performance and efficiency contributed by liquid systems. In electric motors, increased winding temperature raises copper losses (I²R), reducing motor efficiency. This applies directly to the motors used in electric vehicles, which further emphasizes the need for advanced cooling methods. This essay also addresses the challenges associated with liquid cooling, specifically regarding the complexity of structure, the expensive costs, and the long- term stability of advanced coolants. By synthesizing recent international and domestic research, this review presents a framework for optimizing thermal management efficiency and proposes directions for future research.