中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 17 Special 1 November 2007 |
KOH alkaline electrolyte on electrochemical properties of
La2Mg0.9Al0.1Ni7.5Co1.5 h
（1. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials,
Lanzhou University of Science and Technology, Lanzhou 730050, China;
2. Key Laboratory of Non-ferrous Metal Alloys, Ministry of Education,
Lanzhou University of Science and Technology, Lanzhou 730050, China）
Abstract:The influence of the addition of Cu(OH)2 to 6 mol/L KOH alkaline electrolyte on the electrochemical properties of La2Mg0.9Al0.1Ni7.5Co1.5 hydrogen storage alloy electrode was investigated by electron probe X-ray microanalysis(EPMA), X-ray diffraction(XRD) and electrochemical measurements. EPMA micrographs and XRD patterns show that the surface of the hydride electrode is plated by metal copper film. The thickness and compactness of Cu film increase with the increment of charge-discharge cycle number. The copper film of the hydride electrode surface can keep the hydrogen storage alloy particle in the electrode interior from oxidizing availably. The addition of Cu(OH)2 to alkaline electrolyte lowers the activation property and the high rate dischargeability of the La2Mg0.9Al0.1Ni7.5Co1.5 hydride electrode, but has no negative effect on the maximum discharge capacity of the hydride electrode. Moreover, it is effective to improve the cyclic stability of the hydride electrode utilizing electrodeposit Cu film on the La2Mg0.9Al0.1Ni7.5Co1.5 hydride electrodes surface.
Key words: hydrogen storage alloy; electrodeposition; La-Mg-Ni alloy; electrochemical properties
