## Wikipedia - Densità di corrente di scambio (it) Wikipedia - Обмінний струм (uk) exchange current

of an electrode reaction
https://doi.org/10.1351/goldbook.E02238
The common value $$I_{0}$$ of the anodic and cathodic partial currents when the reaction is at equilibrium $I_{0}=I_{\text{a}}=- I_{\text{c}}$ For an electrode at equilibrium at which only one reaction is significant $$I=0$$. When more than one reaction is significant at a given electrode, subscripts to $$I_{0}$$ may be used to distinguish exchange currents. $$I$$ is not usually zero when only one of these reactions is at equilibrium.
Source:
PAC, 1974, 37, 499. (Electrochemical nomenclature) on page 513 [Terms] [Paper]