Advances in metal hydride high-temperature thermal storage systems

As an emerging energy storage method, metal hydride high-temperature thermal storage system has high heat storage density and environmental sustainability, and can be combined with intermittent renewable energy sources such as solar energy to construct a concentrating solar power plant, which has received extensive attention in the energy field in recent years. This technology can realize efficient storage and release of thermal energy through the reversible chemical reaction between metal and hydrogen to form hydride, which improves the stability and reliability of solar photovoltaic power plants. This review summarizes the current research status of this technology, focusing on the progress in the development and screening of materials, the optimal design of reactors, and the optimization of system integration. This paper firstly introduces the power generation systems and principles. The materials chapter focuses on magnesium-, titanium-, and calcium-based hydride materials and introduces the improvement of thermodynamic, kinetic, and cyclic properties and the screening principles of paired metal hydrides; secondly, the objectives and means of reactor optimization in terms of heat and mass transfer are analyzed in detail, and the challenges of scaled-up reactor design are emphasized; finally, the system integration optimization discusses how to achieve the optimal coupling of capacity, efficiency and cost by rationally configuring individual systems. The paper also looks at the challenges and opportunities for future large-scale applications of metal hydride high-temperature thermal storage systems, and emphasizes the importance of material, reactor, and system optimization for their commercialization.