Electrochemical characterization of absorbed hydrogen in stoichiometric and nonstoichiometric hydrogen storage alloys

✍ Scribed by Hiroshi Inoue; Masayoshi Miyamoto; Masao Matsuoka; Yukio Fukumoto; Chiaki Iwakura

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 298 KB
• Volume: 42
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/s0013-4686(96)00254-x

✦ Synopsis

Anodic polarization curves of Mm(Ni~.~Mno.~Al~.~Co~,~), (Mm = misch metal, 0.88 5 x 5 1.12) electrodes were measured under the conditions of various initial concentrations of absorbed hydrogen (H/M), rates of potential sweep and temperatures. Anodic peak current (Z,) at the Mm(Ni~.~M~.4Al~.~Co0.7), electrodes increased with an increase in x value. In addition, the Zp value depended linearly on initial hydrogen concentration and square root of potential sweep rate irrespective of x value. Furthermore, the activation energy for hydrogen diffusion decreased with an increase in x value. From these results, it is considered that the hydrogen diffusion in the Mm(Ni~.~Mn~.~Al~.~Co~.~).~ alloys and the electrocatalytic activity at their surfaces influence the Zp value and that they are important factors for improving the charge-discharge performance of negative electrode.