Solid–liquid phase change materials meet hydrogels: syntheses and multifunctional applications

Abstract

Thermal energy storage (TES) technology has attracted much attention from various industrial fields owing to its high heat storage capacity and versatile energy conversion pathways. Among TES technologies, latent heat storage (LHTES) utilizing solid–liquid phase change materials (PCMs) demonstrates particular promise for practical engineering applications through its mild operational characteristics and minimized temperature fluctuations during energy exchange. Nevertheless, inherent limitations including leakage risks, structural deformation, and intrinsically low thermal conductivity continue to challenge PCM implementation. Recent advancements in materials engineering have pioneered an innovative solution through the development of phase change hydrogels (PCHs), which effectively encapsulate PCMs within three-dimensional polymer networks to create form-stable heat storage composites. Herein, we comprehensively review the synthesis methods, multifunctional applications, and enhancement mechanisms of the PCHs. This review reveals critical interdisciplinary synergies bridging thermal physics, materials science, and chemical engineering. By addressing current technical barriers and outlining future research trajectories, the review aims to stimulate interdisciplinary collaborations and developments.