Research progress and prospect of magnesium alloy phase change energy storage materials: a review

Renewable energy systems, particularly solar power generation, face challenges from inherent intermittency and stochastic power variability. Metallic phase change materials (PCMs) in thermal storage systems provide solutions through high thermal conductivity and superior energy density. This investigation provides a systematic examination of magnesium-based alloy PCMs, encompassing their thermal storage performance (latent heat, phase transition), thermophysical characteristics (thermal conductivity), and performance enhancement methodologies (microencapsulation, compositional optimization). Experimental results demonstrate that Mg-based PCMs exhibit favorable phase transition characteristics within 200–600 ℃, accompanied by latent heat capacities of 20–300 J/g and thermal conductivities ranging from 20 to 140 W·(m·k)⁻¹. The research comprehensively evaluates thermal conductivity enhancement mechanisms, operational performance optimization, and advanced strategies for subcooling mitigation and oxidation/corrosion resistance improvement. While significant progress has been achieved, persistent challenges remain in subcooling regulation and practical implementation. This study suggests three potential areas of studies: (1) synergistic optimization of alloy compositions, (2) development of advanced protective coatings, and (3) multiscale modeling to predict phase evolution, offering valuable insights for material selection and technological advancement in thermal energy storage systems.