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Updated: Oct 20, 2025
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Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation
Published on: October 10, 2018
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Double layer capacitances analysed with impedance spectroscopy and cyclic voltammetry: validity and limits of the
Maximilian Schalenbach1, Yassin Emre Durmus1, Hermann Tempel1
1Fundamental Electrochemistry (IEK-9), Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany. m.schalenbach@fz-juelich.de.
Physical Chemistry Chemical Physics : PCCP
|September 15, 2021
Summary
This study compares cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) for probing electrochemical double layers. Deviations from constant phase element (CPE) behavior occur at higher amplitudes, revealing limitations in impedance calculus.
Area of Science:
- Electrochemistry
- Physical Chemistry
Background:
- Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are standard electrochemistry techniques.
- Constant phase elements (CPEs) are used to model the electrochemical double layer in impedance analysis.
Purpose of the Study:
- To compare the double layer responses measured by CV and EIS.
- To investigate the validity of CPE models under varying potential and amplitude conditions.
Main Methods:
- Probing a gold electrode using CV and EIS under potential and amplitude variations.
- Utilizing an equivalent circuit with a CPE for EIS data and an impedance-based Fourier transform model for CV data.
Main Results:
- CV and modeled responses showed good agreement at low amplitudes (<0.2 V) and specific scan rates.
- At higher amplitudes, CV measurements revealed active changes in double layer ion arrangement, deviating from CPE behavior.
- Standard impedance calculus, assuming sinusoidal response, does not account for these deviations.
Conclusions:
- The study highlights limitations of CPE models in impedance calculus when double layer equilibrium is perturbed.
- CV offers insights into dynamic ion arrangement changes not captured by traditional EIS analysis.
- Understanding these differences is crucial for accurate electrochemical measurements and modeling.
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