Phase change materials (PCMs) having a large latent heat during solid-liquid phase transition are promising for thermal energy storage applications. However, the relatively low thermal conductivity of the majority of promising PCMs (<10 W/ (m ⋅ K)) limits the power density and overall storage efficiency.
Large volumes or high pressures are required for thermal storage of materials in the gas phase, making the system complex and impracticable. As a result, the sole phase change used for heat storage is the solid–liquid phase change . The characteristics of solid–solid and solid–liquid PCMs is shown in Table 1. Table 1.
This upward trend signifies the growing interest and attention directed towards phase change heat storage materials. It is a reflection of the increasing global recognition and adoption low-carbon energy conservation and sustainable development principles. Fig. 2.
The highest observed latent heat of phase change in the fiber samples was 137.05 J/g. Feng et al. also utilized coaxial electrospinning to prepare thermal storage fibers, where the shell material was PU and the core material consisted of PEG.
A detailed numerical analysis was presented by Aljehani et al. to demonstrate the transient behaviour of heat transfer in a phase change thermal energy storage system. On the other hand, Kubinski et al. provided a simplified dynamic model in Aspen HYSYS software.
The article presents different methods of thermal energy storage including sensible heat storage, latent heat storage and thermochemical energy storage, focusing mainly on phase change materials (PCMs) as a form of suitable solution for energy utilisation to fill the gap between demand and supply to improve the energy efficiency of a system.