The Manganese Dioxide Electrode in Alkaline Electrolyte; The Electron-Proton Mechanism for the Discharge Process from MnO[sub 2] to MnO[sub 1.5]

In the study of cathodic reduction of electrolytic manganese dioxide at constant‐current discharge in alkaline electrolytes, effects of , Zn(II) ion added to the electrolyte, and of temperature on the discharge curves of the electrodeposited on a graphite rod were investigated. Results are discussed in view of the electron‐proton mechanism. The potential vs. x value in curve agrees in general with that calculated from corresponding to a reaction which is assumed to take place in one phase of the oxide electrode system . In prepared with , the polarization of the electrode was greater than that in electrolyte prepared with . Addition of zinc ion had no effect on the discharge curve from . A new definition of E° for a homogeneous redox solid system is proposed and the value for the system compared to the conventional thermodynamic E° value. A few potential‐controlling factors of the electrode are discussed.