ABSTRACT
Titanium and iron form two stable intermetallic compounds: TiFe and TiFe2. TiFe was discovered as a metal hydride by J. J. Reilly and R. H. Wiswall. This alloy has been considered to be a promising hydrogen storage material due to its excellent hydrogen storage properties. The TiFe alloy has good thermodynamic properties, good H-capacities, and low raw material cost. Nanocrystalline TiFe has much higher hydrogen solubility at low pressure than conventional TiFe. The application of titanium alloys as electrode materials focused on the electronic structure of TiFe and its modification by mainly nickel atoms as well as molybdenum, chromium, and cobalt impurities. The strong modifications of the electronic structure of the nanocrystalline TiNi-type alloys compared to that of polycrystalline materials could influence its hydrogenation properties. The significant broadening of the valence band for the nanocrystalline TiNi-based alloys could be explained by disorder and strong deformation of the nanocrystals.
