Phase change materials for thermal management of Li-ion batteries in electric vehicles: A comprehensive review

Phase change materials (PCMs) have emerged as effective passive thermal management solutions for electric vehicle (EV) battery systems due to their high latent heat capacity and ability to suppress temperature rise. This review examines recent advancements in PCM-based battery thermal management systems (BTMSs), with particular emphasis on material development, system configurations, and hybrid cooling architectures. The reviewed studies are analyzed based on experimental and numerical investigations under varying C-rates, ambient temperatures, PCM types, and geometric constraints. Results from recent hybrid PCM systems, including fin-embedded, honeycomb, and topology-optimized cold plate configurations, demonstrate reductions of approximately 22–40% in maximum battery temperature and improvements of 2–5 °C in temperature uniformity, depending on operating conditions and design parameters. Furthermore, optimized integration of active cooling components with PCMs has been shown to reduce pumping power and system volume by up to 50%, enhancing overall system efficiency. The review also critically discusses key engineering challenges such as thermal conductivity enhancement, long-term stability, scalability, and cost. Finally, emerging research directions toward intelligent, multifunctional, and sustainable PCM architectures, including bio-based composites and data-driven optimization frameworks, are identified as promising pathways for advancing next-generation EV BTMSs.