The authors present a study of the frequency dependence of the impedance (Z( omega ) varies as (i omega C)^{- eta}) of fractal models for the electrode-electrolyte interface. They will show that the Cantor bar model gives a fractional exponent eta of this impedance for only a very limited range of parameter values while a model based on a Koch curve gives a fractional exponent over a large frequency range for a broad range of parameter values.