Optimization of V-Ti-Fe hydrogen storage alloy based on orthogonal experiments

Abstract

Vanadium-based solid solution hydrogen storage alloys have attracted much attention because of their high hydrogen capacity, mild hydrogen absorption- desorption conditions, and high safety. However, the V-Ti-Fe alloys, developed at low cost, have a relatively low effective capacity and is unsuitable for practical production. In this work, (VxFe100-x)100-yTiy-z%Ce (x=0.83,0.85,0.87; y=16,18,20; z=1,2,3) alloys are designed by orthogonal method to investigate the effect of compositions on the microstructure and hydrogen storage properties. It is shown that the effective hydrogen capacity and desorption plateau pressure of the (VxFe100-x)100-yTiy-z%Ce alloy are related to multiple factors, such as lattice constants, tetrahedral interstitials of the BCC and BCT phases, electron concentration and Vickers hardness. The optimized alloy (V87Fe13)82Ti18-1 %Ce based on the orthogonal experiments shows a reversible hydrogen storage capacity of 2.17 wt% and a desorption plateau pressure of 0.373 MPa at 70°C. The reversible hydrogen capacity of (V87Fe13)82Ti18-1 %Ce is superior to most V-Ti-Fe alloys.