Hydrogen storage properties of vanadium-based b.c.c. solid solution metal hydrides

On the basis of literature reports, several series of vanadium-based solid solutions with a b.c.c. structure were prepared and their hydrogen storage properties were studied in order to develop alloys with high hydrogen capacity and low cost. The V-Ti-Cr alloys were examined by adding other b.c.c. elements (Mn and Fe) and adjusting the corresponding compositions. Increasing the Cr content and the addition of Mn increased the plateau pressure due to lattice contraction, which is beneficial for reducing the first plateau region, although it decreased the maximum hydrogen storage capacity. Furthermore, Mn is an effective element to flatten the plateau pressure. The alloys containing Fe were found to be difficult to activate. A V0.375Ti0.25Cr0.30Mn0.075 alloy was developed which exhibited an effective hydrogen capacity of 2.2 wt% H after annealing at 1300 degreesC for I h. (C) 2002 Elsevier Science B.V. All rights reserved.