  A phenomenological theory of electric double layer polarization of blocking
electrode is presented solving modified Debye-Falkenhagen (MDF) equation for
potential, under the impedance boundary condition. The dynamic impedance and
capacitance are obtained in terms Debye screening length and frequency
dependent polarization length. Two characteristic relaxation frequencies for
compact layer and diffuse layer are identified. At frequencies less than
Helmholtz layer relaxation frequency the EDL is perfectly blocking. At
frequencies larger than the diffuse layer relaxation frequency the EDL behaves
like a resistor. At crossover frequencies the electrode is polarized.
Theoretical results agrees well with experimental capacitance dispersion data.
