The structure and the properties of the electrical double layer (EDL) belong to the fundamental problems of the electrode/solution interface. Several informative reviews on this topic, by B. Damaskin, O. Petrii , W. Fawcett et al. can be found in the special issue "Electrochemistry -Past, Present and Future" of the J. Solid State Electrochemistry . For many years, the conclusions made by the researchers were refuted by subsequent experiments, and many fundamental questions remain unexplored until now. These include, in particular, the Volta problem, understanding the relationship between electromotive force of galvanic cell and the potential drop inside it : Volta, then Nernst, Ostwald, Langmuir; and the first consistent solution in 1928 by A. Frumkin and A. Gorodetztkaya based on the concept of a potential of a zero charge (pzc). But even on the basis of the pzc-concept it is not possible to explain, e.g. the differences observed in different metal/solvent systems, in particular, at the transition to aprotic polar solvents (APS) -DMF, DMSO, et al. In general, the structure of EDL in APSs "remains poorly investigated and the results obtained are still to be substantiated by quantum mechanical approach …and the modern theory of metals" . At the meantime, these solvents began to be widely used in electrochemistry, first in polarography and then in electrosynthesis, from the mid-1950s and early 1960s , : The use of APS greatly extends the available range of cathodic potentials, allows the separation of individual stages, etc. (see further).