Dielectric spectroscopy

Engineering

Oxide

Capacitance

Electrochemistry

Metallurgy

Materials science

Chromatography

Cyclic voltammetry

Linearity

Physical chemistry

Electrical impedance

Capacitive sensing

Electronic engineering

Double-layer capacitance

Analytical Chemistry (journal)

Horizontal scan rate

Chemistry

Electrode

Electrical engineering

Electrochimica Acta

The electric properties of an electrode can be evaluated by the determination of the capacitance. However, the literature reports a large panel of experimental protocols for capacitance determination, which involve either cyclic voltammetry (CV) or electrochemical impedance spectroscopy (EIS). In fact, substantial discrepancies in the assumptions are made between both techniques as in CV, the system is usually considered as ideal (and the current-scan rate relationship is assumed to remain linear at all frequencies), whereas in EIS, the system is usually considered as non-ideal and a CPE element is introduced. In this work, the electric properties of two electrode configurations, namely an Au blocking electrode and an Al electrode with a thin oxide film were investigated using EIS and CV. The capacitive domain was determined for both systems assuming the presence of an ideal and non-ideal system. The results collected from CV revealed a limited linearity between the current and scan rate for both electrode configurations. Finally, a CPE element was introduced to determine the capacitance from CV data and compared to EIS results.

Revisiting cyclic voltammetry and electrochemical impedance spectroscopy analysis for capacitance measurements