Recent advances in chloride molten salt-based thermal energy storage: Melting behavior, modification, and corrosion mitigation strategies

Chloride molten salts, with their exceptional thermal stability, low-cost potential, and compatibility with advanced high-efficiency power cycles, have become the core alternative technology for next-generation high-temperature thermal storage systems. This review provided a comprehensive assessment of the key pillars of chloride molten salt technology. It began with system design and performance characterization, a stage that not only covered component screening and optimization using thermodynamic modeling (CALPHAD) and molecular dynamics (MD) simulations, but also included the summary and characterization of key thermophysical properties. Subsequently, cutting-edge performance modification strategies aimed at enhancing thermal performance were explored, particularly nanoparticle enhancement technology. Focusing on the core challenge of corrosion control, it provided an in-depth analysis of corrosion mechanisms and mitigation techniques. Finally, the current status of the technology in specific applications was outlined. The key conclusion was that despite the significant thermodynamic advantages of chloride molten salts, their inherent and strong corrosivity remained the primary technical obstacle hindering their engineering application. By integrating diverse research topics ranging from chloride molten salt fundamental material design to applied engineering challenges, this review constructed a systematic and complete knowledge framework. This comprehensive overview aimed to provide researchers with a solid scientific reference, clarifying cutting-edge progress and critical knowledge gaps in the field, thereby offering core guidance for the future development and application of chloride molten salt technology.