Application Of Short-time Fourier Research Articles

A comprehensive analysis of impedance of the electrochemical cell

A comprehensive impedance characteristics of two electrodes electrochemical cell has been presented. In this method a multisinusoidal current excitation signal is used. The change of potential of both the electrodes are all registered as a function of time. The proposed method gives the possibility of determining the impedance of both electrodes individually as well as the impedance of a two-electrode system. Additional application of short time Fourier transform of time registers allows the determination of changes in the measured impedance values over time. In order to present the possibilities of the proposed technology it was applied to a process of charging commercially available electrochemical cell NiCd. The new measurement methodology allows understanding the dynamics of processes occurring in a electrochemical cell. This is the basis for the development of effective and affordable electro-catalysts. Thanks to results obtained with Dynamic Electrochemical Impedance spectroscopy (DEIS) method it is possible to understand the mechanisms and kinetics of processes occurring in electrochemical cells while charging.