Rough electrodes in solid and liquid electrochemistry: impact of morphology on the impedance

Abstract

The impact of the electrode morphology on the overall impedance in liquid and solid electrochemistry is discussed for two examples: for an electrode with small surface roughness and for an electrode exhibiting deep, equidistant pores. The impedance is calculated numerically using the finite element method. Non-polarizable as well as ideally and partially polarizable electrodes are considered. The (usually) different wetting behaviour of the electrolytes in solid and liquid electrochemistry leads to qualitatively different impedance spectra. Focusing on solid electrolytes the interplay of linear electrode polarization and current constriction due to imperfect contacts is considered, i.e. in addition to our previous treatment we explicitly allow for a finite transfer resistance.