Microelectrode Studies of Electrochemically Coprecipitated Cobalt Hydroxide in Nickel Hydroxide Electrodes

The role of electrochemically coprecipitated cobalt hydroxide and nickel hydroxide has been investigated at a nickel microelectrode for purposes of elucidating the effect of cobalt hydroxide on the electrode reactions of battery active nickel hydroxide. Hydroxide films were deposited onto the electrode surface from boiling ethanol solutions of in the presence and absence of ; their behavior in 30% solution was studied by cyclic voltammetry, chronoamperometry, and chronocoulometry. In general, the presence of coprecipitated cobalt hydroxide appears to render the charge‐discharge reaction more reversible thereby allowing charging to occur at less positive potentials, this apparently increases the charging efficiency by minimizing concurrent oxygen evolution. The microelectrode was also used to characterize the cathodic deposition process for the nickel hydroxide.