The Proton Diffusion Coefficient for the Nickel Hydroxide Electrode

The diffusion coefficient for protons moving in the hydrated nickel hydroxide lattice has been determined using a potential step technique. It was found to have the value about during charging and during discharging for the nickel hydroxide structure usually found in the nickel electrode of the nickel‐cadmium battery. The temperature dependence of the coefficient has been determined, and it has been concluded that the proton moves in the lattice by thermal diffusion. The enthalpy of diffusion was found to be 2.2 kcal deg⁻¹ mole⁻¹ during charging and 2.3 kcal deg⁻¹ mole⁻¹ during discharging of the electrode.