Visualization of EIS at large potential range - new insights

Abstract: Electrochemical Impedance Spectroscopy (EIS) is an experimental technique largely used in electrochemistry and corrosion studies. However, almost all published papers have just measured the EIS at the corrosion potential, especially for corrosion purposes. This fact limits the capability of the technique. In this paper, a Scilab software was developed which allows the visualization of multiple EIS diagrams regarding the potential, exposure time or experiment run. This procedure was applied to austenitic stainless steels in two electrolytes from cathodic to anodic potentials. The EIS maps with two- or three- dimensions were very useful to depict the evolution of the surface with respect to the large range of applied potential. Some results are shown to highlight the usefulness of this approach as a complementary technique to the DC test performed at a given potential range.