The Debye layer as a transmission line in the 4Hz-100kHz frequency range

We report measurements on the dynamics of the Debye layer at a gold electrode in several electrolytes. In the experiments, the Debye layer transmits a damped voltage wave along the electrode, which we use to probe the dynamics. We compare the measurements with traditional impedance models, which schematize the Debye layer as a capacitance. We find good agreement for very dilute electrolytes, but also for an ionic liquid. However, the same model fails for the concentrated electrolyte, as ion - solvent - ion interactions become important.