Significance of High-Pressure Torsion (HPT) on Solid-State Hydrogen Storage Properties

摘要

This paper reviews some major findings on the significance of severe plastic deformation on the hydrogen storage properties of metal hydrides. The method of high-pressure torsion (HPT) is employed to introduce severe plastic deformation in different Mg-based and Ti-based hydrogen storage materials. Several interesting results are found: increasing the hydrogenation kinetics; easy activation and decreasing the hydrogenation pressure in the first cycles; improvement of the air resistance of the materials and difficult deactivation; and synthesizing new nanostructured hydrogen storage materials. It is shown that these unique properties are due to changes in microstructure and formation of different kinds of lattice defects (dislocations, grain boundaries, stacking faults and fine cracks), which can act as quick pathways for hydrogen transportation. Correlations between the hydrogen storage properties and microstructural features are discussed.