The synthesis and hydrogen storage properties of Mg₂Ni substituted with Cu, Co

Mg₂Ni_1-xCu_x (x = 0, 0.2, 0.4) and Mg₂Ni_1-yCo_y (y = 0, 0.2, 0.4) were successfully synthesized via two steps: induction melting and then ball milling. The component and microstructure of the alloys were determined with x-ray diffraction (XRD) and scanning electron microscopy/x-ray energy-dispersive spectrometry (SEM/XEDS). Mg₂Ni phase was observed in all 5 alloys. When the amount of Cu was increased, it led to the formation of phase from Mg₂Cu to Cu₁₁Mg₁₀Ni₉. Co₂Mg was detected in the Co-containing alloys. The hydrogen absorption/desorption properties were tested with p-C-T measurement apparatus, and the results showed that the gaseous storage properties of the alloys were improved by the addition of Cu or Co.