Electrochimica Acta, Vol.53, No.25, 7386-7395, 2008
Local electrochemical impedance spectroscopy: Considerations about the cell geometry
Local electrochemical impedance spectroscopy provides a powerful tool for the investigation of surface heterogeneities on electrode surfaces. However, measurements are greatly influenced by geometry-induced frequency dispersion. In order to account for this frequency dispersion, both simulations and experiments were performed to explore the influence of a recessed electrode on the local and global impedance response. The calculations presented here demonstrated that the depth of the recessed electrode required to achieve a uniform primary current distribution was twice the electrode radius. The calculations provide guidelines for design of LEIS measurements, and were in good agreement with results obtained for a stainless steel disk electrode in a Na2SO4 electrolyte. (c) 2008 Elsevier Ltd. All rights reserved.
Keywords:local electrochemical impedance spectroscopy (LEIS);uniform primary current distribution;ideally polarized electrode;recessed electrode