Seven steps to reliable cyclic voltammetry measurements for the determination of double layer capacitance

作者：Dulce M. Morales, Marcel Risch · 发表于：Journal of Physics Energy · 年份：2021 · DOI：10.1088/2515-7655/abee33 · 被引用次数：230 · 研究领域：Electrocatalysts for Energy Conversion、Advanced battery technologies research、Conducting polymers and applications

Abstract Discovery of electrocatalytic materials for high-performance energy conversion and storage applications relies on the adequate characterization of their intrinsic activity, which is currently hindered by the dearth of a protocol for consistent and precise determination of double layer capacitance ( C DL ). Herein, we propose a seven-step method that aims to determine C DL reliably by scan rate-dependent cyclic voltammetry considering aspects that strongly influence the outcome of the analysis, including (a) selection of a suitable measuring window, (b) the uncompensated resistance, (c) optimization of measuring settings, (d) data acquisition, (e) selection of data suitable for analysis, (f) extraction of the desired information, and (g) validation of the results. To illustrate the proposed method, two systems were studied: a resistor–capacitor electric circuit, and a glassy carbon disk in an electrochemical cell. With these studies, it is demonstrated that when any of the mentioned steps of the procedure are neglected, substantial deviations of the results are observed with misestimations as large as 61% in the case of the investigated electrochemical system. Moreover, we propose allometric regression as a more suitable model than linear regression for the determination of C DL for both the ideal and the non-ideal systems investigated. We stress the importance of assessing the accuracy of not only highly specialized electrochemical methods, but also of those that are...