Polyphenols on Carbon\nPaper Electrodes: A Fundamental\nStudy for Sustainable Electrochemical Energy Storage

Promoting sustainable electrochemical energy storage\ncan be achieved\nby employing biosourced organic molecules with redox-active motifs.\nStudies focusing on developing high-performance energy storage devices\nbased on redox-active organic molecules often lack a clear understanding\nof the charge transfer mechanisms involving these molecules. Here,\nwe report on a systematic study of the electrochemical behavior of\nbiosourced polyphenols (pyrogallol, catechin, rutin, quercetin, and\nmangiferin) deposited on carbon paper electrodes in aqueous electrolytes,\nto gain insight into their charge transfer mechanisms and reveal possible\nrelationships between (supra)molecular structure-electrochemical properties.\nWe studied the effect on the electrochemical behavior of modified\nelectrodes of mono/divalent metal cations (Li<sup>+</sup>, Na<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, and Zn<sup>2+</sup>) in\nthe supporting electrolyte. Contact angle measurements were used to\ninvestigate the interface of the polyphenols with water and scanning\nelectron microscopy to reveal their supramolecular structures at the\nsurface of the carbon paper electrodes. Electrochemical studies were\nperformed by cyclic voltammetry and electrochemical impedance spectroscopy.\nAs proof of concept, electrodes based on polyphenols and sustainable\nconductive additives were studied in a three-electrode configuration\nfor supercapacitor applications.