The Global and Local Impedance Response of a Blocking Disk Electrode with Local Constant-Phase-Element Behavior
Résumé
Numerical methods were used to calculate the influence of geometry-induced current and potential distributions on the impedance
response of a blocking disk electrode with a local constant-phase element behavior. While the calculated global impedance is
purely capacitive, the local impedance has high-frequency inductive loops that were observed in experiments conducted on a
stainless steel electrode in 0.05 M NaCl + 0.005 M Na2SO4 electrolyte. The calculated global impedance responses are in good
agreement with experimental results obtained using both the steel electrode and a glassy-carbon disk in KCl electrolytes of
differing concentrations. The computed local and both local and global ohmic impedances are shown to provide insight into the
frequency dispersion associated with the geometry of disk electrodes.