The electrochemical hydrogen storage characteristics of as-spun nanocrystalline and amorphous Mg₂₀Ni_10-xM_x（M=Cu, Co, Mn;x=0–4） alloys

Yang-Huan Zhang¹，Tai Yang¹，Hong-Wei Shang¹，Chen Zhao¹，Chao Xu¹，Dong-Liang Zhao²

1. Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology2. Department of Functional Material Research, Central Iron and Steel Research Institute

摘 要：In this paper, we comprehensively investigate the influences of M（M=Cu, Co, Mn） substitution for Ni on the structures and electrochemical hydrogen storage characteristics of the nanocrystalline and amorphous Mg20Ni10-xMx（M=Cu, Co, Mn; x = 0–4） alloys prepared by melt spinning. The as-spun（M=None, Cu） alloys display an entire nanocrystalline structure, whereas the as-spun（M=Co, Mn） alloys hold a mixed structure of both nanocrystalline and amorphous when x = 4（M content）. These results indicate that the substitution of M（M=Co, Mn） for Ni facilitates the glass formation in Mg2Ni-type alloy. All the as-spun alloys have the Mg2 Ni major phase, but M（M=Co, Mn） substitution brings on some secondary phases,such as Mg Co2, Mg phases for M=Co, and Mn Ni, Mg phases for M=Mn. The substitution of M（M=Cu, Co, Mn）for Ni also makes a positive contribution to the cycle stability of the alloys in the following orders:（M=Cu） [（M=Co） [（M=Mn） for x = 1 and（M=Co） [（M=Mn）[（M=Cu） for x = 2–4. Meanwhile, it notably enhances the discharge capacity of the alloys in the sequence of（M=Co） [（M=Mn） [（M=Cu）. As for the high rate discharge ability, it visibly upgrades with the growing of M content for（M=Cu, Co）, while it grows at first and then declines for（M=Mn）.

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