World Journal of Engineering Research and Technology

Nasirudeen K. Raji*, Seong W. Lee

ABSTRACT

Phase change materials (PCMs) have emerged as promising candidates for thermal energy storage due to their high latent heat storage capacity and nearly isothermal phase transition behavior. However, their widespread deployment in practical heat storage systems remains constrained by several intrinsic limitations, including low thermal conductivity, leakage during phase transition, phase segregation, supercooling, and long-term thermal instability. While substantial research efforts have primarily focused on enhancing thermal conductivity, growing evidence suggests that conductivity improvement alone is insufficient to achieve optimal system-level performance. This critical review therefore adopts a holistic perspective to evaluate performance optimization strategies for PCMs beyond thermal conductivity enhancement. Key approaches reviewed include composite formulation, encapsulation and shape-stabilization techniques, geometry-driven heat transfer enhancement, long-term durability, and sustainability considerations. Emphasis is placed on the complex trade-offs between thermal conductivity, latent heat retention, structural stability, charging–discharging rates, and long-term reliability. Emerging trends such as hybrid nanocomposites, additive manufacturing-enabled structures, and sustainability-driven PCM design are also discussed. Finally, current research gaps and future directions are identified to bridge the disconnect between laboratory-scale material development and scalable, application-ready thermal energy storage systems.

[Full Text Article] [Download Certificate] https://doi.org/10.5281/zenodo.22267136