Hydrogen storage properties of V + TiFe_(0.85)Mn_(0.15) multi-phase alloys made by mechanical alloying

摘要

The mechanical alloying technique was used to make multi-phase alloys V+ TiFe_(0.85)Mn_(0.15). Their hydrogen storage properties were characterized and compared with that of the polycrystalline alloys made by casting. It was found that the ball milled alloys can absorb hydrogen at room temperature in the first cycle without prior activation. The 40 % V + 60% TiFe_(0.85)Mn_(0.15) alloy made by mechanical alloying shows the best hydrogen storage property with the valid hydrogen capacity up to 220 mL/g at 293 K and 4.0 MPa, and the P-C-T behavior is also improved. The XRD and EDX analyses also show that the phase of these alloys contains V, TiFe, γ-TiMnx, TiFe_2 and α-FeV. The composition of these phases affects significantly the hydrogen storage properties of alloys.