Ti–V–Mn based metal hydrides for hydrogen storage

Abstract

• Ti 0.47 V 0.46 Mn and Ti 0.50 V 0.51 Mn alloys were produced by arc melting. • Compositional differences led to different unit cell volumes for the C14 Laves phase. • Change in composition caused a significant change in plateau pressure and hysteresis. Two Ti–V–Mn BCC-Laves phase alloys with the nominal composition Ti 0.5 V 0.5± x Mn ( x = −0.04 and 0.01), were synthesised by arc melting. This compositional difference resulted in different compositions and unit cell volumes for the C14 Laves phase. Ti 0.47 V 0.46 Mn and Ti 0.50 V 0.51 Mn demonstrated reversible hydrogen sorption capacities of 1.53 and 1.56 ± 0.05 wt.% (at 120 bar H 2 at 303 K) respectively, however, the change in composition results in a small change in the enthalpy of hydride decomposition, and a significant change in plateau pressure and hysteresis. This may allow for the plateau pressure to be tuned to meet the requirements of different solid-state hydrogen storage applications.