Enhancement of Thermal Conductivity in Phase Change Materials for Thermal Energy Storage Applications: A Comprehensive Review

Abstract

Phase Change Materials (PCMs) are widely recognized for their high latent heat capacity and stable thermal performance, making them ideal for thermal energy storage (TES) applications. However, their inherently low thermal conductivity limits charging and discharging rates, reducing system efficiency. This review presents recent advancements in enhancing the thermal conductivity of PCMs through nanoparticle dispersion, structural modification, and hybrid enhancement strategies. Studies involving metallic and metal oxide nanoparticles (Cu, Al₂O₃, Ag, CuO), carbon-based nanomaterials (graphene, CNTs, graphite), and novel nanostructures (MnO₂ nanowires/nanotubes) are discussed. The effects of nanoparticle type, concentration, container geometry, and hybrid systems combining fins, heat pipes, and nanoparticles are systematically analyzed. The review concludes that graphene-based and MnO₂-based nanocomposites offer superior thermal performance with minimal impact on latent heat, making them promising candidates for future TES technologies.