Hydrogen storage properties of La1-xYxNi4.8Mn0.2 alloys

The influences of Y content on the crystal structure, hydrogen storage thermodynamics and kinetics, and pulverization resistance of La1-xYxNi4.8Mn0.2 (x=0.6, 0.7, 0.8) alloys were investigated systematically. The results show that all the alloys have CaCu5 type hexagonal structure; with increasing Y content, the lattice parameter a, crystal volume V decreased, while the lattice parameter c kept almost unchanged, and c/a increased linearly. With the increase of Y content, the absorption/desorption plateau pressures increased dramatically; however, the hydrogen storage capacity decreased; the slopes of hydrogen absorption/desorption plateau declined, and the hysteresis increased lightly; A similar variation trend was presented between the hysteresis and FWHM (the full width at half maximum) of (111) XRD patterns with increasing Y content; the pulverization resistance improved. When Y content x=0.8, the alloy showed good performance both in the hydrogen absorption and desorption. © right.