Influence of the addition of vanadium on the hydrogenation properties of the compounds TiFe0.9Vx and TiFe0.8Mn0.1Vx (x = 0, 0.05 and 0.1)

TiFe0.9 and TiFe0.8Mn0.1 hydrides have suitable equilibrium pressures at ambient conditions and are potential candidates for hydrogen storage applications. In this work, we study the influence of the addition of small amounts of vanadium on the hydrogenation properties of TiFe0.9Vx and TiFe0.8Mn0.1Vx (x = 0, 0.05 and 0.1) alloys. The excess of Ti from TiFe in these materials results in the precipitation of Ti and Ti2Fe-type phases. In the analysis of the chemical composition, vanadium was observed in small amount in all phases for each sample which contains vanadium. Vanadium tends to substitute Fe sites, which results in a decrease of the plateau pressures. The addition of vanadium as TiFe0.8Mn0.1Vx (x = 0.05 and 0.1) alloys has beneficial effects on the equilibrium plateaus of the hydrides: the plateaus become flatter and a significant reduction in the pressure hysteresis is observed.

Research highlights
► Characterisations of the system Ti–Fe(Mn)–V with CsCl structure type.
► Increase of the absorption capacity of TiFe0.9.
► Decrease of the hysteresis factor for the TiFe system.