Effect of Different Species of Cobalt Additive on Performance of Nickel Hydroxide Electrode

Performances of nickel electrodes when adding or without adding Cobalt in different forms were studied, the results were interpreted by cyclic voltammetry(CV) and electrochemical impedance spectroscope (EIS). It was demonstrated that the additions of Co, CoO, CoO+Co by mechanically mixing with Ni(OH)2 all can improve the performance of nickel electrode to some extent, and when Co is added in the form of CoO the best performance can be obtained. This can be mainly attributed to the fact that three kinds of Co additives all improved the structure of nickel hydroxide and the ability of H+ in electrolyte transporting through the material, hence the reversibility of nickel electrode and the oxygen evolution potential are increased. These improved the charging efficiency of nickel electrode, accordingly, improved the performance of nickel electrode.