2‐Methoxyhydroquinone from Vanillin for Aqueous Redox‐Flow Batteries
Werner Schlemmer, Philipp Nothdurft, Alina Petzold, Gisbert Rieß, Philipp Frühwirt, Max Schmallegger, Georg Gescheidt‐Demner, Roland C. Fischer, Stefan A. Freunberger, Wolfgang Kern, Stefan Spirk
Abstract
Abstract We show the synthesis of a redox‐active quinone, 2‐methoxy‐1,4‐hydroquinone (MHQ), from a bio‐based feedstock and its suitability as electrolyte in aqueous redox flow batteries. We identified semiquinone intermediates at insufficiently low pH and quinoid radicals as responsible for decomposition of MHQ under electrochemical conditions. Both can be avoided and/or stabilized, respectively, using H 3 PO 4 electrolyte, allowing for reversible cycling in a redox flow battery for hundreds of cycles.
Topics & Concepts
RedoxChemistryHydroquinoneElectrochemistryRadicalSemiquinoneAqueous solutionElectrolyteQuinoneFlow batteryPhotochemistryVanillinDecompositionInorganic chemistryCombinatorial chemistryOrganic chemistryElectrodePhysical chemistryAdvanced battery technologies researchElectrocatalysts for Energy ConversionElectrochemical Analysis and Applications