Recent advances in phase change materials-based battery thermal management systems for electric vehicles

Electric vehicles' lithium-ion batteries (LIBs) generate abundant heat during charging and discharging. Controlling the batteries' temperature within the appropriate range using a battery thermal management system (BTMS) is critical to ensure electric vehicle batteries' safety, efficiency, and cycle life. As phase change materials (PCMs) possess characteristics of large latent heat, good temperature uniformity, and no extra energy consumption, they are ideal materials for applications in BMTS. This paper reviews the enhanced properties of PCMs, including thermal conductivity, flame retardancy, and electrical insulation. The PCM-based BTMS is investigated, covering the active phase change fluid (PCF) based-BTMS and hybrid BTMS. Considering the operating conditions of electric vehicles, low-temperature environments, and vibrations are inevitable. Therefore, the application of PCM in battery preheating is presented, which comprises preheating with PCMs alone and hybrid methods. The random vibration of the vehicle caused by the road is transmitted to the BTMS, and the effect of vibration on the BTMS is discussed. Finally, the results of several studies on the application of PCMs in BTMS are summarized, and future research directions have been prospected.