• PCM classifications and key criteria for selecting suitable PCM materials. • Thermal, physical, and chemical factors in PCM material selection. • Explores enhancement methods to address PCM issues like leakage and low conductivity. • Highlights diverse PCM applications in energy, electronics, and building systems. Phase change materials (PCMs) have gained significant attention for their role in thermal energy storage (TES) applications, including renewable energy systems, building climate control, electronic cooling, and industrial waste heat recovery. Their ability to store and release large amounts of latent heat during phase transitions makes them highly efficient energy-storage solutions. However, inherent limitations, such as inadequate thermal conductivity, phase instability, supercooling phenomena, and leakage, impede their practical deployment and compromise long-term operational reliability. This review provides a comprehensive analysis of recent advancements in PCM enhancement strategies to overcome these limitations and improve system performance. Key techniques for thermal conductivity enhancement include the incorporation of high-conductivity nanoparticles, metallic fins, and porous structures, which facilitate a faster and more uniform heat transfer. Among these enhancement strategies, fins have demonstrated superior heat transfer performance compared to nanoparticle doping owing to their cost-effectiveness, straightforward fabrication, and ability to significantly enhance both melting and solidification rates. Furthermore, shape-stabilized phase-change materials (SSPCMs) utilizing graphene aerogels, expanded graphite, and polymer-grafted materials effectively mitigate leakage issues while maintaining thermal efficiency. Microencapsulation using polymer and inorganic shells enhances phase stability and durability, whereas eutectic PCM blends and salt hydrate stabilization address phase separation and supercooling concerns. Additionally, the integration of advanced composite materials, flexible TES modules, and multifunctional PCM-TES systems has extended their applicability across various industries. Recent innovations have enabled real-time performance adjustments based on environmental conditions and energy demand, further improving efficiency and adaptability. This review highlights the critical role of these advancements in enabling high-performance PCM-TES systems, paving the way for more sustainable and efficient thermal energy storage solutions.
Aamir Sohail (Sun,) studied this question.