Optimizing hydrogen ad/desorption of Mg-based hydrides for energy-storage applications

Hydrogen energy is expected to be an "ideal fuel" in the era of decarbonization. The discovery, de-velopment, and modification of high-performance hydrogen storage materials are the keys to the fu-ture development of solid-state hydrogen storage and hydrogen energy utilization. Magnesium hydride (MgH2), with its high hydrogen storage capacity, abundant natural reserves, and environmental friend-liness, has been extensively researched. Herein, we briefly summarize the typical structure and hy-drogenation/dehydrogenation reaction mechanism of MgH2 and provide a comprehensive overview of strategies to effectively tune the thermodynamics and kinetics of Mg-based materials, such as alloy-ing, nanosizing, the introduction of additives, and composite modification. With substantial efforts, great achievements have been achieved, such as lower absorption/desorption temperatures and better cy-cling stability. Nonetheless, some pivotal issues remain to be addressed, such as unfavorable hydro-genation/dehydrogenation factors, harsh conditions, slow kinetics, incomplete dehydrogenation, low hy-drogen purity, expensive catalysts, and a lack of valid exploration of mechanisms in the hydrogena-tion/dehydrogenation process. Lastly, some future development prospects of MgH2 in energy-efficient conversion and storage have been presented, including advanced manufacturing ways, stabilization of nanostructures, the introduction of additives combined with structural modification, and utilization of advanced characterization techniques.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.