Advances in thermal energy storage: Fundamentals and applications

Thermal energy storage (TES) is increasingly important due to the demand-supply challenge caused by the intermittency of renewable energy and waste heat dissipation to the environment. This paper discusses the fundamentals and novel applications of TES materials and identifies appropriate TES materials for particular applications. The selection and ranking of suitable materials are discussed through multi-criteria decision making (MCDM) techniques considering chemical, technical, economic and thermal performance. The recent advancements in TES materials, including their development, performance and applications are discussed in detail. Such materials show enhanced thermal conductivity, reduced supercooling, and the advantage of having multiple phase change temperatures (cascade PCMs). Nano-enhanced PCMs have found the thermal conductivity enhancement of up to 32% but the latent heat is also reduced by up to 32%. MXene is a recently developed 2D nanomaterial with enhanced electrochemical properties showing thermal conductivity and efficiency up to 16% and 94% respectively. Shape-stabilized PCMs are able to enhance the heat transfer rate several times (3-10 times) and are found to be best suited for solar collector and PV-based heat recovery systems. Cascade and molten slats PCMs find their best applications in the thermal management of buildings and the power sector (concentrated solar plants). Microencapsulated, nanoPCMs and shape-stabilized PCMs effectively reduce the supercooling of hydrated salts. The recent trends of TES materials in various applications, including building, industrial, power, food storage, smart textiles, thermal management, and desalination are also briefly discussed. Finally, future research in advanced energy storage materials is also addressed in this study, which is intended to help create new insights that will revolutionize the thermal management field.