Abstract:The oxidative energy storage behaviors of a designed novel system comprising a nickel hydroxide film electrode and an oxygen-reducing platinum cathode were investigated by various electrochemical techniques. The structure and morphology of samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. It is found that the oxidative energy storage in the Ni(OH)₂ electrodes can be obviously enhanced in the coupling system containing the cathode electrolytes with higher oxygen content or lower pH value. The results of the oxidation−discharge cycle tests show that the Ni(OH)₂ film electrode oxidized in the coupling system with 1.0 mol/L Na₂SO₄ (pH=2) as cathode electrolyte for 600 s presents discharge capacities of 79.0 mC/cm² at the first cycle and 97.9 mC/cm² at the 12th cycle, suggesting the excellent reversibility of the investigated oxidative energy storage and conversion system.

Key words: oxidative energy storage; nickel hydroxide film; oxygen-reducing cathode; oxidation