Recent Advances in Pickering Emulsion Templated Phase Change Material Microcapsules: Design, Fabrication, and Multifunctional Applications

The increasing demand for efficient thermal energy storage systems has driven the development of phase change material microcapsules (PCMMs), which provide high energy‐storage density, reversible phase change, and reduced leakage. Conventional microencapsulation methods for phase change materials (PCMs) (e.g., coacervation, solvent evaporation, and spray drying) suffer from limitations such as the use of toxic reagents, poor mechanical stability, and leakage. In contrast, the Pickering emulsion templating method employs solid nanoparticles to stabilize PCM‐based emulsions, followed by polymerization of organic monomers or inorganic precursors at the oil–water interfaces to create shells, enabling greener processing, higher encapsulation efficiency, superior mechanical and thermal robustness, and tunable shell properties. This review systematically examines the workflow of PCMM fabrication via the Pickering emulsion templating method, covering: 1) PCM classification, phase change mechanisms, and thermal properties; 2) preparation of PCM‐based Pickering emulsions; 3) formation of microcapsule shells; and 4) post‐treatments. The underlying structure–property relationships are also evaluated to clarify the impact of architectural design on thermal storage capacity and mechanical durability. Subsequently, a critical review of their utility in several application fields, such as energy devices and flexible electronics, functional fibers and smart coatings, building materials and cryogenic transportation, environmental remediation, and drug delivery, is provided. Finally, current challenges and future directions are discussed to guide translation into practical thermal energy applications.