Voltammetry of Constant Phase Elements: Analyzing Scan Rate Effects

Je, Hyeonsu; Chang, Byoung-Yong

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J. Electrochem. Sci. Technol > Accepted Articles

Research Article

DOI: https://doi.org/10.33961/jecst.2024.00318 [Accepted]
Published online April 22, 2024.

Voltammetry of Constant Phase Elements: Analyzing Scan Rate Effects

Hyeonsu Je, Byoung-Yong Chang

Department of Chemistry, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan 608-739, Korea

Correspondence: Byoung-Yong Chang, Tel: +82-51-629-5597, Fax: +82-51-629-5583,
Email: bychang@pknu.ac.kr

Received: 18 March 2024 • Accepted: 12 April 2024

Abstract

Here we introduce a new method for characterizing the constant phase element (CPE) in electrochemical systems using cyclic voltammetry (CV), presenting an alternative to the conventional electrochemical impedance spectroscopy (EIS) approach. While CV is recognized for its diagnostic capabilities in electrochemical analysis, it traditionally encounters difficulties in accurately measuring CPE systems due to a lack of clear linearity with scan rates, unlike capacitors. Our research demonstrates a linear relationship between current and scan rate on a log-log plot, enabling the calculation of n and Y0 values for CPE from the slopes of these linear relationships. For validation of our method, it is applied to two kinds of capacitors and the results agree with those measured by EIS. Although EIS is known to be accurate in measuring CPE systems, our alternative approach offers a timely and reasonably precise diagnostic tool, balancing between ease of use and accuracy, especially beneficial for preliminary assessments before conducting further in-depth analysis.

Key Words: cyclic voltammogram, constant phase element, electrochemical impedance