Liquid Cooling–PCM Composite Thermal Management Systems for Lithium-Ion Power Batteries in Electric Vehicles: A Review

Abstract

With the rising demand for fast charging and high-rate operation of new energy vehicles, lithium-ion power batteries generate increasing heat during charge and discharge. This conditions result in cell heat accumulation and module thermal imbalance. Excessively high operating temperatures accelerate battery capacity degradation, shorten cycle life, and increase safety risks. Meanwhile, large temperature gradients impair cell-to-cell consistency and limit the overall performance of battery packs. Therefore, efficient and reliable battery thermal management systems (BTMS) for high heat flux applications improve lithium-ion power battery performance. This paper investigates liquid cooling-PCM composite thermal management systems for lithium-ion power batteries in electric vehicles. Besides, it reviews the development status, heat transfer mechanisms, structural features, operating conditions, control strategies, and optimization methods for active, passive, and composite architecture. The study indicates that the liquid cooling-PCM composite thermal management system combines PCM heat storage with liquid cooling heat dissipation, reducing peak temperature and boosting thermal uniformity. However, additional weight, cost, and control complexity remain key challenges. Future work should focus on lightweight high-conductivity PCM composites, efficient control strategies, and aging-aware optimization.