Effect of Ni concentration on the structural and hydrogen storage characteristics of Zr–Mn based laves phase system

The present communication reports the hydrogen storage characteristics of ZrMn2−xNi x laves phase hydrides. It is observed that promising hydrogen storage materials can be tailored when “x” is in the range of 1.5 ≤ x ≥ 1. The materials formed within this range reversibly store ~2 to ~3 H/F.U. under manageable operating conditions. The composition ZrMn0.5Ni1.5 is found to absorb and desorb hydrogen under room temperature. The other two compositions ZrMn0.75Ni1.25 and ZrMnNi absorb ~3.6 H/F.U. and release ~3 and ~3.2 H/F.U., respectively. In each case, almost half of the effective storage capacity of total can be reversibly stored within 5 s under room temperature. Therefore, the materials falling within the range of 1.5 ≤ x ≥ 1 are promising candidates for stationary device applications. The correlation between the compositions, structural–microstructural features and thermodynamic data are presented.