Study on the modification of Zr-Mn-V based alloys for hydrogen isotopes storage and delivery

To ensure the safety and efficiency of hydrogen isotopes in the storage and delivery system (SDS), Zr-Mn-V based hydrogen isotopes storage alloys were prepared by induction levitation melting technique under Ar atmosphere. The effects of modification for Zr-Mn-V alloy of ZrMn2-xVx (x = 0, 0.4, 0.6, 0.8) and ZrMn1.4-yV0.6 (y = 0, 0.2, 0.4) on microstructure, hydriding kinetics, de-/hydrogenation thermodynamics, cycling stability and anti-disproportionation performance were systematically investigated. The results show that all alloys contain a main phase of ZrMn2 and little impure phase. Crucially, the lattice parameters of ZrMn2 phase increase after V substitution, as well as Mn decrease, leading the equilibrium pressure of dehydrogenation significantly decreases from 2.931 bar (ZrMn2-H) to 0.080 bar (ZrMn1.2V0.6-H) at 200 °C, and the corresponding enthalpy changes from 43.29 to 60.38 kJ mol−1 H2. Compared with ZrCo, ZrMn1.2V0.6 exhibits outstanding stability with 1.63 wt% during 20 cycles and scarcely losing on capacity through the anti-disproportionation measurement under the simulated SDS environment. Consequently, considering all the performances of ZrMn1.2V0.6 sample, it could be an alternative material for hydrogen isotopes storage and delivery to be applied in SDS.