Microstructures and hydrogen storage properties of ZrFe2.05−xVx (x = 0.05–0.20) alloys with high dissociation pressures for hybrid hydrogen storage vessel application

•The substitution of V for Fe in ZrFe2.05−xVx alloys is studied.•The C15 lattice parameters and unit cell volumes increase with the increase in x.•The capacity of hydrogen storage of alloys increases with the increase in x.•The hysteresis factor of alloys decreases with the increase in x.•The substitution of V for Fe improves the activation and kinetics of alloys.

The microstructures and the hydrogen absorption/desorption properties of ZrFe2.05−xVx (x = 0.05, 0.10, 0.15, 0.20) alloys have been studied by XRD, SEM/EDS, P-C isotherm and hydrogen absorption kinetics measurements. It is found that the C15 Laves phase is the dominant phase of the alloys and its lattice parameters and unit cell volumes increase with increase in the V substitution, but the C14 Laves minor phase appears when x is over 0.15. As the result, the capacity of hydrogen storage of the alloys increases and the hysteresis factor decreases with increase in the V concentration. The activation and hydrogen absorption kinetics of the alloys are also sufficiently improved by the substitution of V for Fe.