Review of Micro/Nanoencapsulated Phase-Change Materials for Thermal Energy Storage in Moderate Thermal Environments

Phase-change materials (PCMs) are widely recognized for their potential in high-efficiency thermal energy storage. However, direct use or matrix impregnation often leads to leakage and reduced performance, and no single PCM possesses all of the ideal properties. Micro/nanoencapsulation provides a feasible solution by preventing leakage and enabling multifunctional integration via core@shell structures. Despite extensive research, micro/nanoencapsulated PCMs in moderate thermal environments (∼10–60 °C) have received comparatively little attention. This review aims to systematically analyze the categories, fabrication methods, and applications of micro/nanoencapsulated (∼10 nm–100 μm) PCMs in buildings, textiles, batteries, and other moderate-temperature systems. The main challenges are highlighted, particularly the low thermal conductivity that limits the energy charging/discharging efficiency. To address this, experimental methods, numerical simulations, and emerging deep learning approaches such as physics-informed neural networks are discussed, which integrate physical laws with data-driven learning to improve prediction accuracy and reduce computational cost. Therefore, this work not only provides a systematic and interdisciplinary perspective on micro/nanoencapsulated PCMs in moderate thermal environments but also outlines future pathways for enhancing heat transfer performance and accelerating their practical deployment in energy, construction, and electronic applications.