Highly Efficient Hydrogen Storage Capacity of 2.5 wt % Above 0.1 MPa Using Y and Cr Codoped V-Based Alloys

Effective hydrogen storage capacity is a key factor for applications of solid-state hydrogen storage technology. In this work, V-based solid solution alloys were prepared and the effect of codoping Cr and the rare-earth Y element on the crystal microstructure and reversible hydrogen storage properties were investigated. The results revealed that the hydrogen absorption of Ti–V–Mn–Cr–Y alloys could exceed 90% of the maximum hydrogen capacity within 50 s at 6 MPa hydrogen pressure, and the alloy Ti0.9Y0.1V1.1Mn0.8Cr0.1 can absorb maximum 3.71 wt % hydrogen capacity, and the effective hydrogen capacity above 0.1 MPa can reach 2.53 wt % at 423 K. Furthermore, the dehydriding thermodynamic parameters revealed a significant tendency toward easier dehydrogenation with codoping of trans-metal and rare-earth metal elements.