The atmosphere, consisting of ions, that surrounds an individual ion in an electrolyte. In the absence of an electric field each anion is surrounded by a symmetrical accumulation of cations and vice versa. When an electric field is applied the anions migrate to the anode and the cations to the cathode. The symmetry of the ionic atmosphere is therefore disturbed with respect to the surrounded ion, and the ions experience a retarding force due to the migration of the opposite-polarity ionic atmosphere in the opposite direction.

If high-frequency alternating current or a fast-pulse direct current is applied to the electrolyte, the symmetry is little disturbed and a higher conductivity of electrolyte results.