Origin and interpretation  of Electrode potential

                              Electrode potential appears at the interface between an electrode and electrolyte due to the transfer of charged species across the interface, specific adsorption of ions at the interface, and specific adsorption/orientation of polar molecules, including those of the solvent.

Electrode Potential is the electric potential on an electrode component. In a cell, there will be an electrode potential for the cathode, and an electrode potential for the anode. The difference between the two electrode potentials equals the cell potential. The electrode potentials value does not depend on the species in the reaction, therefor the electrode potential for a half reaction of 2Cu2+(aq)+4e- -----> 2Cu(s) has the same electrode potential as Cu2+ (aq) +2e- -----> Cu (s) <<Electrochemistry Ch 19. Ebbing, Darrell; Gammon, Steven D.>>

The measured electrode potential may be either that at equilibrium on the working electrode ("reversible potential"), or a potential with a non-zero net reaction on the working electrode but zero net current ("corrosion potential", "mixed potential"), or a potential with a non-zero net current on the working electrode (like in galvanic corrosion or voltammetry). Reversible potentials can be sometimes converted to the standard electrode potential for a given electroactive species by extrapolation of the measured values to the standard state      .

The value of the electrode potential under non-equilibrium depends on the nature and composition of the contacting phases, and on the kinetics of electrode reactions at the interface (see Butler-Volmer equation).