Enhancement of Ti-Cr-V BCC alloys on the dehydrogenation kinetics of Li-Mg-N-H hydrogen storage materials

The hydrogen storage properties of a Li-Mg-N-H material doped by a 4 mol.% Ti3Cr3V4 body centre cubic（BCC） alloy hydride and prepared with a ball-milling method were investigated by X-ray diffraction,scanning electron microscopy,transmission electron microscopy and Sievert＇s technology test.The results show that the Ti3Cr3V4 BCC alloy hydride/Li-Mg-N-H composite has good reversible hydrogen storage properties.The dehydrogenation kinetics of the Li-Mg-N-H system can be greatly improved by doping the Ti3Cr3V4 BCC alloy hydride.The composite desorbed 4.1 wt.% hydrogen in the first 60 min at 473 K under 0.1 MPa pressure,but when without the BCC alloy addition,only 3.0 wt.% hydrogen was desorbed under the same dehydrogenation condition.It can be deduced that the Ti3Cr3V4 BCC alloy uniformly distributed in the Li-Mg-N-H substrate could decrease the activating energy of hydrogen molecules to H atoms and increase H diffusion paths in the composite,enhancing the dehydrogenation kinetics of the Li-Mg-N-H system.