Nonstoichiometric Ti-Zr-Ni-V-Mn alloys: the effect of composition on hydrogen sorption and electrochemical characteristics

The effect of the stoichiometric factor on the electrochemical and gas-phase behavior of hydride-forming intermetallic alloys of the Ti0.45Zr0.55NiyV0.45Mnx general composition is studied. The structure and the phase composition of the alloys were investigated by means of X-ray diffraction, electron microscopy, and electron probe microanalysis. An introduction of hydrogen does not change the structure type and hydriding is accompanied by an isotropic increase in the cell volume by about 20%. The alloys studied demonstrate maximum values of hydrogen sorption capacity, discharge capacity, and good rate capability throughout a wide range of compositions, rather than in a narrow region in the vicinity of the stoichiometric composition.