Semiconductor electrochemistry approach to the study of oxide films on nickel electrodes

Impedance measurements and photoeffect studies on nickel electrodes were carried out to characterize the oxide films on such electrodes. It was found that an n-type or p-type semiconducting oxide can be present at the surface of a nickel electrode. Impedance measurements show that a solid-state diffusion process, presumably of protons through the oxide film, dominates the impedance behavior for the charged electrode; for the discharged electrode, the impedance behavior is dominated by the space charge inside the p-type oxide. By using semiconductor electrochemistry techniques, fundamental insights about the kinetics of battery electrodes can be obtained. All the additives tested are impurities that influence battery performance; some for the better, most for the worse.