Effect of substituting Ni with Cu on the cycle stability of La{sub 0.7}Mg{sub 0.3}Ni{sub 2.55-x}Co{sub 0.45}Cu {sub x} (x = 0-0.4) electrode alloy prepared by casting and rapid quenching
- School of Material, Inner Mongolia University of Science and Technology, Baotou 014010 (China)
- School of Material, Inner Mongolia University of Science and Technology, Baotou 014010 (China) and Department of Functional Material Research, Central Iron and Steel Research Institute, 76 Xueyuan Nan Road, Haidian District, 100081 Beijing (China)
- Department of Functional Material Research, Central Iron and Steel Research Institute, 76 Xueyuan Nan Road, Haidian District, 100081 Beijing (China)
In order to improve the cycle stability of the La-Mg-Ni system (PuNi{sub 3}-type) hydrogen storage alloy, Ni in the alloy was partly substituted by Cu. Hydrogen storage alloys La{sub 0.7}Mg{sub 0.3}Ni{sub 2.55-x}Co{sub 0.45}Cu {sub x} (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by casting and rapid quenching. The effects of substituting Ni with Cu and the quenching rate on the microstructures and the cycle stability of the as-cast and quenched alloys were investigated in detail. The results obtained by X-ray diffraction show that the as-cast and quenched alloys have a multiphase structure, including the (La, Mg)Ni{sub 3} phase, the LaNi{sub 5} phase and the LaNi{sub 2} phase, and the amount of the LaNi{sub 2} phase increased with the increase of the Cu content. The substitution and rapid quenching have an inappreciable influence on the phase compositions of the alloys, but both obviously changed the phase abundances of the alloys. The results derived by transmission electron microscopy confirm that the substitution of Cu for Ni is favourable for the formation of an amorphous phase in the as-quenched alloys. The results obtained by the electrochemical measurement indicate that substituting Ni with Cu improved the cycle stability. When the Cu content increases from 0 to 0.4, the cycle lives of the as-cast and rapidly solidified alloys increased from 72 cycles to 88 cycles and from 100 cycles to 122 cycles, respectively.
- OSTI ID:
- 21003542
- Journal Information:
- Materials Characterization, Vol. 58, Issue 3; Other Information: DOI: 10.1016/j.matchar.2006.05.005; PII: S1044-5803(06)00154-9; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
- Country of Publication:
- United States
- Language:
- English
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