The impedance of an electrochemical cell can also appear to be inductive. Some authors have ascribed inductive behavior to adsorbed reactants. Both the adsorption process and the electrochemical reaction are… read more →
Solution resistance is often a significant factor in the impedance of an electrochemical cell. A modern three-electrode potentiostat compensates for the solution resistance between the counter and reference electrodes. However,… read more →
Whenever the potential of an electrode is forced away from its value at open circuit, this is called polarizing the electrode. When an electrode is polarized, it can cause current… read more →
Diffusion can create an impedance known as the Warburg impedance, which depends on the frequency of the potential perturbation. At high frequencies the Warburg impedance is small because diffusing reactants… read more →
An electrical double layer exists at the interface between an electrode and its surrounding electrolyte. This double layer is formed as ions from the solution “stick to” the surface of… read more →
A capacitor is formed when two conducting plates are separated by a non-conducting medium, called the dielectric. The value of the capacitance depends on the size of the plates, the… read more →
Capacitors in EIS experiments often do not behave ideally. Instead they act like a constant phase element (CPE) as defined below. The impedance of a CPE has the form: When… read more →
A similar resistance to electrolyte resistance is formed by a single kinetically-controlled electrochemical reaction. In this case we do not have a mixed potential, but rather a single reaction at… read more →