Ion migration in hydride materials

Of particular interest in the present study is ion migration in hydrides. Such motion has profound implications for dynamic H absorption/desorption into/from the lattice of hydrides for hydrogen storage, purification, and separation. The proton/electron transfers from the lattice to its surface for chemical reactions as well as charge transfer across its bulk phase for solid-state electrolytes (SSEs), etc. This progress report presents the recent achievements in alkali/alkaline-earth ion and H- conduction in hydrides. We survey strategic approaches for the design and optimization of these materials for ion conduction, which include anion engineering, cation substitution, complexing, and interfacial engineering. We also briefly discuss the challenges and research directions for hydride-based ion conductors.