Hydrogen storage properties of V30–Ti–Cr–Fe alloys

The hydrogen storage properties of V–Ti–Cr–Fe alloys with the compositions of V(30 at.%)–Ti(15–55 at.%)–Cr(7–43 at.%)–Fe(2–18 at.%) were studied in this paper. It was found that the hydrogen absorption capacities and the efficient hydrogen capacities of the alloys are dependent on the Ti/(Cr + Fe) ratio. The largest efficient hydrogen capacity is obtained at a Ti/(Cr + Fe) ratio of 1.0. When Ti/(Cr + Fe) ratio increases from 0.9 to 1.05, the lattice parameters of the alloys and the enthalpy of the hydrides grow, while the hydrogen desorption plateau pressure declines. The alloy of V30Ti35Cr25Fe10, which contains a high Fe content and a low V/Fe ratio of 3:1, exhibits a hydrogen capacity of 3.6 wt.% and an efficient hydrogen capacity of 2.0 wt.% at 298 K.