Verlagslink DOI: 10.1016/j.electacta.2025.145707
Titel: A correlated multi-observable assessment for vanadium redox flow battery state of charge estimation : long-term stability of methods
Sprache: Englisch
Autorenschaft: Janshen, Niklas 
Chica, Antonio 
Struckmann, Thorsten  
Schlagwörter: Vanadium redox flow battery; State of charge; Long-term stability
Erscheinungsdatum: 29-Jan-2025
Verlag: Elsevier
Zeitschrift oder Schriftenreihe: Electrochimica acta 
Zeitschriftenband: 517
Projekt: „VaMoS“ - Entwicklung eines online Vanadium-Monitoring-Systems zur Bestimmung des Ladungszustandes von Vanadium-Redox-Flow-Batterien 
Zusammenfassung: 
Accurate half cell specific state of charge (SOC) monitoring is needed for vanadium redox flow batteries (VRFB) to quantify electrolyte imbalances and to increase operation efficiency by appropriately timed re-balancing. However, electrolyte crossover shifts the vanadium concentrations and can impact the SOC estimation in combination with side reactions in the long run. As a result, the long-term stability of any SOC estimation is crucial for its accuracy, while a rigorous cross-evaluation of SOC monitoring methods for VRFBs is still missing in the literature. In this study, we investigate the long-term stability for SOC monitoring based on half cell electrolyte potentials, electrolyte densities, electrolyte volumes, electrolyte viscosity related pressure drops, pH related potentials and UV/Vis absorbances. We conduct 500 h long-term charge/discharge cycling for a membrane with 100 µm thickness and 300 h for a 50 µm thin membrane. For each cycle, we determine reference SOCs validated by potentiometric titration, which enables us to calculate calibration parameter for each SOC estimation method in each cycle. We analyze the variation and stability of these parameters and assess the long-term accuracy of each method. The highest long-term stability is shown by the UV/Vis absorbance measured at 400 nm in the negative half cell with estimation errors below 2 % and the electrolyte half cell potentials with errors below 2.5 %. The UV/Vis absorbance measured at 580 nm in the positive half cell exhibits a moderate stability with estimation errors lower than 5 %. The electrolyte densities and pressure drops measured in the negative half cell show moderate stabilities with estimation errors below 7.5 % which could allow for accurate SOC estimation with more frequent re-calibrations.
URI: https://hdl.handle.net/20.500.12738/17037
ISSN: 1873-3859
Begutachtungsstatus: Diese Version hat ein Peer-Review-Verfahren durchlaufen (Peer Review)
Einrichtung: Fakultät Technik und Informatik 
Department Maschinenbau und Produktion 
Heinrich-Blasius-Institut für Physikalische Technologien 
Dokumenttyp: Zeitschriftenbeitrag
Hinweise zur Quelle: article number: 145707
Sponsor / Fördernde Einrichtung: Bundesministerium für Wirtschaft und Klimaschutz 
Enthalten in den Sammlungen:Publications without full text

Zur Langanzeige

Seitenansichten

31
checked on 04.04.2025

Google ScholarTM

Prüfe

HAW Katalog

Prüfe

Volltext ergänzen

Feedback zu diesem Datensatz


Diese Ressource wurde unter folgender Copyright-Bestimmung veröffentlicht: Lizenz von Creative Commons Creative Commons