Hydrogenation Character and Crystal Structures of Hydrides in RMgNi₄ (R = Nd, Gd, Er)

Abstract

Whether the pseudo-binary RNi₂ compounds consistent with the criterion rA/rB = 1.37 for HIA. The hydrogenation performances and crystal structures of the pseudo-binary RMgNi₄ (R = Nd, Gd, Er) were investigated at fixed R/Mg ratio equal to 1. The pseudo-binary RMgNi₄ (R = Nd, Gd, Er) compounds can repetively absorb and desorb hydrogen without the occurrence of HIA and decomposition during hydrogen absorption and desorption cycles at 298 K, 6 MPa. The HIA criterion r_A/r_B of pseudo-binary RMgNi₄ alloys should be higher than 1.37 at fixed R/Mg equal to 1.

Fig. 4 Variation curve of hydrogen storage capacity with cycle number at 298 K.