Impedance spectroscopy of surfaces described by irreversible thermodynamics

It is shown how one can derive the impedance of a polarized electrode surface from irreversible thermodynamics. The oxygen electrode is studied as an example. A Nyquist diagram is constructed for the case that the electrode conducts by electrons only, and the electrolyte conducts by oxygen ions or vacancies. The electrode surface contributes to the diagram with two semi-circles. One semi-circle is due to production of dipoles from adsorbed oxygen atoms. The other is due to the dipole moment of the ion-electron hole pair.