Impacts of Melt Spinning and Element Substitution on Electrochemical Characteristics of the La–Mg–Ni-based A₂B₇-Type Alloys

Yang-huan Zhang, Hong-wei Shang, Ying Cai, Zhong-hui Hou, Guo-fang Zhang, Dong-liang Zhao

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

DOI: 10.4236/ampc.2012.24B022                

Abstract

The partial substitution of Zr for La has been performed in order to ameliorate the electrochemical hydrogen storage performances of La–Mg–Ni based A₂B₇-type electrode alloys. The melt spinning technology was used to prepare the La_0.75-xZr_xMg_0.25Ni_3.2Co_0.2Al_0.1 (x=0, 0.05, 0.1, 0.15, 0.2) electrode alloys. The impacts of the melt spinning and the substituting La with Zr on the structures and the electrochemical hydrogen storage characteristics of the alloys were systemically investigated. The analysis of XRD and TEM reveals that the as-cast and spun alloys have a multiphase structure, composing of two main phases (La, Mg)₂Ni₇ and LaNi₅ as well as a residual phase LaNi₂. The electrochemical measurement indicates that both the substitution of Zr for La and the melt spinning ameliorate the electrochemical cycle stability of the alloys dramatically. Furthermore, the high rate discharge ability (HRD) of the as-spun (10 m/s) alloys notably declines with growing the amount of Zr substitution, while it first augments and then falls for the (x=0.1) alloy with rising the spinning rate.

Keywords

A₂B₇-Type Alloy; Substituting La with Zr; Melt-Spinning; Electrochemical Characteristics

Conflicts of Interest

The authors declare no conflicts of interest.

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