Gas hydrogen absorption and electrochemical properties of Mg24Ni10Cu2 alloys improved by Y substitution, ball milling and Ni addition

Abstract

Mg24Ni10Cu2 and Mg22Y2Ni10Cu2 alloys were prepared via vacuum induction melting, and the nanocrystalline/amorphous Mg24Ni10Cu2 and Mg24Ni10Cu2 + 100 wt% Ni alloys were synthesized through ball milling method. Microstructure and hydrogen storage properties of the alloys were investigated and compared as well. The results suggest that adding Ni in the milling process significantly promotes formation of amorphous and nanocrystalline structure. For these four alloys, the as-milled Mg24Ni10Cu2 with 100 wt% Ni shows the best hydrogen storage performances that 2.03 wt% hydrogen content can be absorbed just in 1 min, and the electrochemical capacity reaches to 899.2 mAh/g. Furthermore, ball milling with Ni promotes the charge transfer reaction and hydrogen diffusion ability which is advantageous to the high rate discharge ability.