A review on phase change materials employed in Li-ion batteries for thermal management systems

Heat generated during lithium -ion batteries (LIBs) operation can lead to side reactions involving safety hazards, including fire and explosion, if not effectively dissipated. To address this challenge, the use of an efficient battery thermal management system (BTMS) is essential to regulate temperature within safe operating limits. Hence, this article provides a comprehensive review of lithium batteries and energy storage batteries, encompassing their classification, working principles, structural features, and heat generation mechanisms. A BTMS classification was proposed according to the most studied systems that were identified: Air-cooled, Liquid-cooled, Heat pipe-cooled, and phase change material (PCM)-cooled BTMS. Furthermore, a detailed analysis was conducted on PCM utilization in BTMS, according to its classification, selection criteria, properties enhancement methodologies, and applications. Notably, paraffins and inorganic compounds emerged as promising options for BTMS, with phase change temperatures ranging from 31.0 to 72.0 degree celsius, latent heats from 35.0 to 210.0 J/g, and thermal conductivities of 0.5 to 9.3 Wm(-1)K(-1). The integration of BTMS approaches, such as active and passive cooling, demonstrated potential in reducing power consumption and improving temperature uniformity within LIBs. Inorganic salt hydrates also showed promise in storing and managing heat during thermal runaway, suppressing its propagation, as supported by the 'nail penetration test'. Additionally, the study highlights the growing utilization of industrial waste materials, such as bischofite, known for their cost-effectiveness. It also outlines future trends in BTMS, including active and passive cooling strategies, accurate heat generation modelling, and the potential of nano-enhanced PCM-cooled BTMSs, which could offer improved thermal conductivity. These findings offer a valuable resource for researchers, engineers, and industry professionals engaged in BTMS development and optimization, providing insights into the efficient management of heat for enhanced safety and performance.