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Investigating the V(II)/V(III) electrode reaction in a vanadium redox flow battery – A distribution of relaxation times analysis

Schilling, Monja; Zeis, Roswitha

Abstract:

Vanadium Redox Flow Batteries (VRFBs) are already commercially available and promise to provide excellent prerequisites to face the challenge of large-scale energy storage. Nevertheless, the VRFB itself has to overcome challenges regarding lifetime and efficiency. Polarization and pumping losses due to a high electrolyte flow-through resistance in the electrode contribute to much of the efficiency losses. We investigated the reaction and processes in the negative VRFB half-cell using electrochemical impedance spectroscopy combined with the distribution of relaxation times analysis. We identify the individual processes in the negative half-cell by varying several parameters. One peak is observed in the low-frequency range below 2 mHz, attributed to the ion transport. In the range from 2 mHz to 1 Hz, several peaks are identified and assigned to the redox-active species' transport processes through the electrode's porous structure. In the high-frequency range above 1 Hz, the single peak was assigned to the electrochemical reaction in the negative half-cell. The processes in this half-cell are slower than in the positive half-cell. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000175643
Veröffentlicht am 28.10.2024
Originalveröffentlichung
DOI: 10.1016/j.electacta.2024.143771
Scopus
Zitationen: 3
Web of Science
Zitationen: 3
Dimensions
Zitationen: 3
Cover der Publikation
Zugehörige Institution(en) am KIT Helmholtz-Institut Ulm (HIU)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 10.02.2024
Sprache Englisch
Identifikator ISSN: 0013-4686
KITopen-ID: 1000175643
Erschienen in Electrochimica Acta
Verlag Elsevier
Band 477
Seiten Art.-Nr.: 143771
Vorab online veröffentlicht am 03.01.2024
Nachgewiesen in Scopus
Web of Science
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