Pseudocapacitance is the electrochemical storage of electricity in an electrochemical capacitor (Pseudocapacitor). This faradaic charge transfer originates by a very fast sequence of reversible faradaic redox, electrosorption or intercalation processes on the surface of suitable electrodes. Pseudocapacitance is accompanied by an electron charge-transfer between electrolyte and electrode coming from a de-solvated and adsorbed ion. One electron per charge unit is involved. The adsorbed ion has no chemical reaction with the atoms of the electrode (no chemical bonds arise) since only a charge-transfer takes place.