ElectrochemistryThe fast charge-transfer reaction of the polycrystalline Ag/Ag+-electrode was studied using a new technique of high-impedance spectroscopy working in the frequency range between 1 kHz and 5 MHz. The method is characterized by a special electrochemical cell with two working electrodes, a new designed dc-control being completely ac-decoupled, a highly precise impedance measurement technique (ICEP = Impedance Conversion and Error Processing) and the quantitative calculation of the electrodynamic field distribution. The accuracy of the measurements is better than 0.05%. The results obtained in the Ag/Ag+-system are in a quantitative agreement with a theoretical transfer function based on a 2-D inhomogeneous surface model. The exchange current densities were found to be about half an order of magnitude higher than the literature data.