Best practices for electrochemical characterization of supercapacitors

We discuss here essential aspects of the experimental supercapacitors characterization by a series of well-known electrochemical methods. We are motivated by a considerable number of publications that misreport procedures and results. Authors often conceal or neglect essential information about the electrochemical analytical apparatus used and its configuration. The lack of such information may lead researchers, especially inexperienced ones, to misunderstand the procedures and results. Eventually, the misled electrochemical equipment configuration favors misinterpretation of data and low reproducibility rates. This paper aims to highlight these issues and clarify them. We explain fundamental concepts of some electrochemical analytical methods, such as cyclic voltammetry, galvanostatic charge–discharge, single potential step chronoamperometry, and electrochemical impedance spectroscopy, focusing on the supercapacitor field. Distinct configurations of electrical parameters are presented and discussed to highlight the effects of incorrect setup and uncover misleading results. We discuss how the electrochemical setup and data analyses matter in reliable data results for the supercapacitor.