EFFECT OF HYDROGEN ON DISCHARGE BEHAVIOR OF THE NICKEL-OXIDE ELECTRODE

The effect of hydrogen on the discharge behaviour of the nickel oxide electrode has been investigated in 30% KOH solution at 25°C. Open-circuit potentials of the nickel oxide electrodes, previously fully charged, decrease more rapidly in a hydrogen atmosphere than in an argon environment. Voltammograms of the nickel oxide electrode show that the amount of cathodic charge decreases considerably when the nickel oxide electrode is exposed to hydrogen rather than to argon. These results, along with X-ray diffraction data, indicate that hydrogen can increase the self-discharge rate of the nickel oxide electrode as a result of reduction of β-NiOOH to β-Ni(OH)2 and the simultaneous oxidation of hydrogen. In addition, hydrogen can produce changes in the nickel oxide electrode during charge that persist to modify discharge behaviour and open-circuit potential. © 1990 Chapman and Hall Ltd.