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Understanding efficient phosphorus-functionalization of graphite for vanadium flow batteries

Radinger, Hannes ORCID iD icon 1; Hartmann, Mark; Ast, Marius 1; Pfisterer, Jessica 1; Bron, Michael; Ehrenberg, Helmut 1; Scheiba, Frieder 1
1 Institut für Angewandte Materialien – Energiespeichersysteme (IAM-ESS), Karlsruher Institut für Technologie (KIT)

Abstract:

Numerous surface treatment methods are known to enhance the electrochemical activity of graphite felt (GF), such as thermal activation or attachment of nanoparticulate catalysts. The integration of heteroatoms into the graphite lattice at the surface could be a promising technique for reliable and efficient electrode activation. However, these functionalization techniques are based on thermochemical activation, which makes it difficult to distinguish between activity effects other than foreign atom integration, such as defects and other surface groups that must be considered. In this work, we analyzed commercial and synthetic phosphorus-doped graphene and GF using different electrochemical and physicochemical techniques. Despite a high doping concentration, the activity of the commercial powder bonded to GF and coated on glassy carbon remained limited due to the low degree of graphitization and high oxygen content. Instead, a low phosphorus concentration of <1 at% combined with a high degree of graphitization increased the catalytic activity. Building on these findings, GF was rationally modified, resulting in twice the power density compared to the original material in full cell tests.


Verlagsausgabe §
DOI: 10.5445/IR/1000150247
Veröffentlicht am 31.08.2022
Originalveröffentlichung
DOI: 10.1016/j.electacta.2022.139971
Scopus
Zitationen: 4
Web of Science
Zitationen: 3
Dimensions
Zitationen: 4
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Materialien – Energiespeichersysteme (IAM-ESS)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 03.2022
Sprache Englisch
Identifikator ISSN: 0013-4686
KITopen-ID: 1000150247
HGF-Programm 38.02.01 (POF IV, LK 01) Fundamentals and Materials
Erschienen in Electrochimica Acta
Verlag Elsevier
Band 409
Seiten Art.-Nr.: 139971
Schlagwörter Vanadium redox flow battery; Electrocatalytic activity; Graphite electrode; Phosphorus doping; Surface functionalization
Nachgewiesen in Web of Science
Dimensions
Scopus
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