According to the IUPAC definition,1 mixed potential is the potential of an electrode (against a suitable reference electrode, often the standard hydrogen electrode) when an appreciable fraction of the anodic or cathodic current arises from two or more different redox couples, but when the total current on the electrode remains at zero.
IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "mixed potential". doi:10.1351/goldbook.M03944 /wiki/International_Union_of_Pure_and_Applied_Chemistry ↩