Influence of Severe Plastic Deformation on Kinetics and Thermodynamics of Various Kinds of Hydrogen Storage Materials: Significance of Grain Boundaries and Lattice Defects

Solid-state hydrogen storage is considered a promising and environmentally friendly approach for energy storage. However, several challenges, including sluggish hydrogen absorption/desorption kinetics and high dehydrogenation temperatures, continue to limit the practical implementation of many hydrogen storage materials. This review summarizes recent advances in the application of severe plastic deformation techniques to improve the hydrogen storage performance of some of the most promising material systems, including TiFe-based intermetallic compounds, titanium alloys such as Ti–V-based alloys and Ti–Mg-based alloys, LaNi5, niobium, palladium, high-entropy alloys, and magnesium and Mg-based materials. Processing routes such as high-pressure torsion, equal-channel angular pressing, fast forging, accumulative fold-forging, and intensive cold rolling have been widely employed to introduce lattice defects, promote grain refinement, and generate a high density of grain boundaries in bulk materials to enhance their hydrogen storage kinetics, activation and air resistance. In addition to enhancing hydrogen absorption and desorption kinetic properties, these techniques offer potential pathways for synthesis of hydrogen storage materials with suitable thermodynamics for hydrogen storage at room temperature. There are also attempts to scale up material production by these techniques. This review paper discusses how plastically deformed materials generally exhibit superior hydrogen storage performance and improved cycling stability compared with their undeformed counterparts.