Ti-V-Mn based metal hydrides for hydrogen compression applications

Ti-V-Mn based alloys, consisting mainly of the hexagonal C14 Laves and BCC phases, with nominal compositions of Ti0.5V0.4TM0.1Mn, where TM = Nb, Cr, Mo, Ta and Ti0.5V0.5−xNbxMn, where x = 0.05 and 0.2, were synthesised by arc melting. It was found that small amounts of Nb substituted for V (x = 0.05 and 0.1) resulted in smaller hysteresis between absorption and desorption as well as higher hydrogen dissociation pressures, compared to Ti0.5V0.5Mn. These findings show that Ti0.5-V0.45-Nb0.05-Mn is a suitable alloy to be used in a metal hydride compressor to deliver a pressure of 650 bar in the temperature range 303-473 K.