A novel experimental method for potential controlled electrochemical impedance spectroscopy

Abstract  In many cases, impedance spectroscopy on electrochemical systems is performed in combination with a potentiostat. The common way of combining a potentiostat and a frequency response analyzer has a number of restrictions. Bandwidth limitations and artifacts from the setup distort the impedance data in sometimes unpredictable manners, and special care has to be taken in physical interpretation of such data. Therefore, potential controlled measurement of artifact-free impedance spectra in a wide range of frequencies is desirable. In this work, a novel experimental method is presented in which the more reliable two-probe impedance spectroscopy is combined with a potential control by a potentiostat without interfering each other. Results obtained on passive zinc by two-probe EIS, the classical potentiostat—EIS combination and the new setup are compared with each other. For an application of the proposed method in measurements of solid state systems, the specific problems are discussed. Graphical abstract