Frequential identification of an electrochemical cell impedance using fractional modeling

International audienceElectrochemical Impedance Spectroscopic (EIS) represents an important technique to characterize the impedance of electrochemical systems. The internal impedance phenomena can be modeled using Electrical Equivalent Circuit. Fractional operator is used to characterize the charge transfer and the diffusion phenomena. This may be attractive due to the ability of fractional systems to be simulated either in frequency or time domain. The impedance model using fractional systems is represented by a transfer function that is identified using Levenberg-Marquardt algorithm. The fractional model identification is validated on an experimental test-bench using two platinum electrodes immersed into Ferri-Ferro solution. Results indicate the ability of fractional system to identify properly the different impedance parameters. In order to decrease the long experiment time of EIS, minimization of the low frequency measurement points is performed and results show the ability of fractional systems to identify EIS data