Ideally polarizable electrode (also ideal polarizable electrode or ideally polarized electrode), in electrochemistry, is an electrode characterized by an absence of net current between the two sides of the electrical double layer, i.e., no faradic current between the electrode surface and the electrolyte. Any transient current that may be flowing is considered non-faradic.
Ideally polarizable electrode is contrasted with ideally non-polarizable electrode, for which a faradic current can freely pass (without polarization).
The classical examples of the two ideal types of electrodes, polarizable and non-polarizable, are the platinum electrodes and the silver/silver chloride, respectively.
The concept of the ideal polarizability has been first introduced by F.O. Koenig in 1934.