  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.

Mesoscale and Nanoscale Physics;Chemical Physics