Effect of Cr content on hydrogen storage properties for Ti-V-based BCC-phase alloys

The phase structures and hydrogen absorption–desorption properties of Ti–25V−xCr–(35−x)Mn alloys were investigated. It was found that the increase of Cr content in the alloys is effective for obtaining a single BCC-phase structure, which results in an increasing hydrogen capacity and a flat hydrogen sorption plateau. The plateau slope of hydrogen sorption in the Ti–25V−xCr–(35−x)Mn system is closely correlated with the strain energy of interstitial site, exhibiting minima at x=10 at which concentration a well-defined plateau is formed. The maximum and effective hydrogen storage capacities among studied alloys are 3.99 and 2.44 wt%, respectively.