Hurdles to organic quinone flow cells. Electrode passivation by quinone reduction in acetonitrile Li electrolytes
Rueda García, Daniel (Institut Català de Nanociència i Nanotecnologia)
Dubal, Deepak P. (Institut Català de Nanociència i Nanotecnologia)
Huguenin, Fritz (Institut Català de Nanociència i Nanotecnologia)
Gómez-Romero, Pedro 1959- (Institut Català de Nanociència i Nanotecnologia)

Date:	2017
Abstract:	The uses of quinones in Redox Flow Batteries (RFBs) has been mainly circumscribed to aqueous solutions (of derivatives with polar groups) despite a larger solubility and wider electrochemical window provided by organic media. The redox mechanism of quinones in protic media is simpler and better known than in aprotic media, where radical species are involved. This paper reports the behaviour of methyl-p-benzoquinone (MBQ) under electrochemical reduction conditions in a LiClO[sbnd]CHCN electrolyte and various working electrodes. We detected the reversible generation of a bright green coating on the working electrode and the subsequent formation of a polymer (the nature of which depends on the presence or absence of oxygen). These coatings prevent the regular redox process of methyl-p-benzoquinone from taking place on the surface of the electrode and is generated regardless of the electrode material used or the presence of O in solution. In addition to MBQ, the green passivating layer was also found for less sterically hindered quinones such as p-benzoquinone or 1,4-naphthoquinone, but not for anthraquinone. We have also shown the central role of Li in the formation of this green layer. This work provides important guidelines for the final use of quinones in RFBs with organic electrolytes.
Grants:	Ministerio de Economía y Competitividad MAT2015-68394-R Ministerio de Economía y Competitividad SEV-2013-0295
Note:	Altres ajuts: Beatriu de Pinós (BP-DGR-2013)
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Redox flow batteries ; Organic electrolyte ; Quinone ; Lithium electrolyte ; Electrode passivation
Published in:	Journal of power sources, Vol. 350 (May 2017) , p. 9-17, ISSN 0378-7753

DOI: 10.1016/j.jpowsour.2017.03.048

Postprint 21 p, 1.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles