Electrochemical Impedance of Blocking Quasi‐Fractal 3‐d Electrodes

The response of ideally polarizable electrodes often exhibits a behavior such as , where is a constant andη a number smaller than one. Recently an expression for the impedance of two‐dimensional (2‐d) self‐similar electrodes, based on the iteration of a simplified equivalent circuit, has been proposed and experimentally verified. These developments, extended to 3‐d objects, allow us to predict the impedance and quantitatively interpret previous results for ramified electrodes. The impedance response presents two frequency domains. In the low‐frequency range, a behavior similar to that of planar electrodes is observed with a surface equal to the total area of the object. At high frequencies, a fractal constant phase angle behavior is found to be quantitatively compatible with our theoretical prediction.