Applications of Kramers-Kronig relations

Abstract

Nowadays, electrochemical impedance spectroscopy has become a quite familiar method because it brings important information regarding the processes that taking place at the interface between the electrode and the electrolyte solution. The main issue with this method is the veracity of the data obtained, because sometimes we get negative or the order of Teraohms values for resistances or in the case of the Nyquist diagram we obtain distorted circles. The accuracy of the data we obtained can be checked applying Kramers-Kronig transforms, which implies the determination of the real part if the imaginary part is known and vice versa. The purpose of this paper is to check, using Kramers-Kronig relations, the data we obtained, in a previous work [3] for 2 supercapacitors, briefly EDLC (Electrochemical Double-Layer Capacitor) with the capacitance values of 5F and 22F through electrochemical impedance spectroscopy.