A novel, environmentally friendly and facile method for oxidative energy storage in nickel hydroxide film electrodes

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.