Surface analysis, hydrogen adsorption and
electrochemical performance of
alkali-reduce treated hydrogen storage alloy
electrochemical performance of
alkali-reduce treated hydrogen storage alloy
(1.Department of Chemistry,Zhejiang University,
Hangzhou 310027,China;
2.Department of Materials Science and Engineering,
Zhejiang University, Hangzhou 310027,China;
3.Department of Physics,Zhejiang University,Hangzhou 310027,China;
4.State Key Laboratory of Silicon Materials Science,
Zhejiang University,Hangzhou 310027,China)
Hangzhou 310027,China;
2.Department of Materials Science and Engineering,
Zhejiang University, Hangzhou 310027,China;
3.Department of Physics,Zhejiang University,Hangzhou 310027,China;
4.State Key Laboratory of Silicon Materials Science,
Zhejiang University,Hangzhou 310027,China)
Abstract: The hydrogen storage alloy powders (MlNi4.0Co0.6Al0.4,Ml=rich-La mischmetal) were treated in a hot 6mol/L KOH+0.02mol/L KBH4 solution,the surface compositions and chemical states of the treated and untreated alloys were analyzed by XPS and EDX, the hydrogen adsorption on the surface of these alloys was evaluated by thermal desorption spectroscopy (TDS),the effects of the surface treatment on the electrochemical performances of the alloy electrodes were investigated. The results show that the hydrogen adsorption is greatly strengthened by the surface modification, and hence leads to marked improvement in the electrocatalytic activity, the treated alloy exhibits higher exchange current density and lower apparent activation energy for the hydrogen electrode reaction than the untreated alloy.
Key words: hydrogen storage alloy;surface treatment;thermal desorption spectroscopy (TDS);eletrocatalytic activity;apparent activati on energy