Kaolinite-based form-stable phase change materials for thermal energy storage

Thermal energy storage has emerged as a prominent and rapidly expanding area of renewable energy research. It holds significant promise in enhancing energy efficiency, supporting environmental protection, and promoting conservation efforts. Among the various approaches, phase change materials (PCMs) have garnered attention due to their impressive latent heat capacity and ability to store thermal energy during phase transitions. In this context, natural 1:1 type layered clay minerals, specifically the kaolinite (Kaol) group minerals, have emerged as a noteworthy option for thermal energy storage. Kaol group minerals possess remarkable attributes such as high thermal conductivity, a large specific surface area, effective adsorption capacity, excellent chemical stability, cost-effectiveness, and environmental friendliness. The inherent interlayer space and natural porosity of these minerals further contribute to the improved thermal cycle stability and shape retention of PCMs. This review primarily focuses on the utilization of Kaol group minerals as a matrix for form-stable PCMs (FSPCMs) in thermal energy storage applications. It thoroughly explores the structures and properties of these minerals, summarizes the processes involved in the preparation and characterization of kaolinite-based FSPCMs, discusses their applications, and elucidates the heat storage mechanism based on storage space and thermal conductivity. Furthermore, it delves into the potential challenges and future prospects associated with kaolinite-based FSPCMs as functional matrices for thermal energy storage and conservation. By examining the energy storage potential of kaolinite-based FSPCMs, this review article aims to deepen our understanding of their characteristics and benefits, and promote their utilization across various domains beyond just thermal energy storage.