Polynomial description of dynamic impedance spectrogram—Introduction to a new impedance analysis method

Abstract

This paper presents a polynomial description of spectrograms obtained using Dynamic Electrochemical Impedance Spectroscopy. A method to fit the polynomial degree correctly is discussed. A simple electrical system of a diode connected in parallel with a capacitor was used for testing. Dynamic impedance measurements during potentiodynamic polarization were conducted. This paper presents an alternative analysis method that allows the determination of system electrochemical characteristics. This method was compared to classical analysis based on equivalent circuit fitting. An alternative method of analysis yielded many advantages in describing impedance results—the potential to obtain an infinite number of impedance spectra over a various range and the possibility to show the resistance and capacitance characteristics as a function of frequency and control of electrochemical energy sources. The polynomial description marks a step forward in analysis automation, facilitating easy and reliable automation and control of electrochemical energy sources.

Keywords

• Dynamic Electrochemical Impedance Spectroscopy
• Impedance spectra analysis
• Polynomial impedance analysis
• Impedance spectra description