A study of VO2+/VO2+ and V3+/V2+ reactions on carbon-based electrodes – correlating reaction kinetics to electrode surface properties

Vanadium redox flow battery (VRFB) shows great potential for large scale energy storage. The reaction kinetics of V3+/2+ and VO2+/VO2+ limit its efficiency. Carbon-based electrodes are typically used in VRFBs. Controversial results are reported in the literature on how the surface properties of carb...

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Main Authors: Chaojie Song, Roberto Neagu, Khalid Fatih
Format: Article
Language:English
Published: Elsevier 2025-07-01
Series:Next Energy
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Online Access:http://www.sciencedirect.com/science/article/pii/S2949821X25000717
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author Chaojie Song
Roberto Neagu
Khalid Fatih
author_facet Chaojie Song
Roberto Neagu
Khalid Fatih
author_sort Chaojie Song
collection DOAJ
description Vanadium redox flow battery (VRFB) shows great potential for large scale energy storage. The reaction kinetics of V3+/2+ and VO2+/VO2+ limit its efficiency. Carbon-based electrodes are typically used in VRFBs. Controversial results are reported in the literature on how the surface properties of carbon electrodes affect the reaction kinetics. In this work, 6 carbon based electrodes (Graphite rod presoaked in H2SO4 (Graphite-soaked), Graphite-untreated, Graphite-Pine, Edge plane pyrolytic graphite, Basal plane graphite, and glassy carbon (GC)) are studied with respect to the electrochemical surface property and reaction kinetics of VO2+/VO2+ and V3+/2+ redox couples. Cyclic voltammetry reveals that capacitance, carbonyl group density, and carboxylic group density of studied electrodes are dependent on the type of electrode and that soaking in H2SO4 leads to an increase in capacitance and functional group density. Diffusion coefficient, charge transfer coefficient, and reaction rate constant for both VO2+/VO2+ and V3+/2+ reactions are also dependent on the type of electrode. The diffusion coefficient of VO2+ increase linearly with the logarithm of carbonyl group density, and that of V3+ increase linearly with the logarithm of capacitance and carbonyl group density. Kinetic current is calculated from the charge transfer coefficient and reaction rate constant, and correlated to the surface properties. For VO2+ to VO2+ reaction, slightly stronger relationship is observed for kinetic current vs logarithm of carbonyl group density than that vs the logarithm of capacitance and carboxylic group. For the V3+ to V2+ reaction, weak relationship between kinetic current and all the 3 properties are found.
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spelling doaj-art-9a0103c3345e404bb8b999851762bc2a2025-08-20T02:30:03ZengElsevierNext Energy2949-821X2025-07-01810030810.1016/j.nxener.2025.100308A study of VO2+/VO2+ and V3+/V2+ reactions on carbon-based electrodes – correlating reaction kinetics to electrode surface propertiesChaojie Song0Roberto Neagu1Khalid Fatih2Corresponding author.; Clean Energy Innovation, National Research Council Canada, 4250 Wesbrook Mall, Vancouver, BC V6T 1W5, CanadaClean Energy Innovation, National Research Council Canada, 4250 Wesbrook Mall, Vancouver, BC V6T 1W5, CanadaClean Energy Innovation, National Research Council Canada, 4250 Wesbrook Mall, Vancouver, BC V6T 1W5, CanadaVanadium redox flow battery (VRFB) shows great potential for large scale energy storage. The reaction kinetics of V3+/2+ and VO2+/VO2+ limit its efficiency. Carbon-based electrodes are typically used in VRFBs. Controversial results are reported in the literature on how the surface properties of carbon electrodes affect the reaction kinetics. In this work, 6 carbon based electrodes (Graphite rod presoaked in H2SO4 (Graphite-soaked), Graphite-untreated, Graphite-Pine, Edge plane pyrolytic graphite, Basal plane graphite, and glassy carbon (GC)) are studied with respect to the electrochemical surface property and reaction kinetics of VO2+/VO2+ and V3+/2+ redox couples. Cyclic voltammetry reveals that capacitance, carbonyl group density, and carboxylic group density of studied electrodes are dependent on the type of electrode and that soaking in H2SO4 leads to an increase in capacitance and functional group density. Diffusion coefficient, charge transfer coefficient, and reaction rate constant for both VO2+/VO2+ and V3+/2+ reactions are also dependent on the type of electrode. The diffusion coefficient of VO2+ increase linearly with the logarithm of carbonyl group density, and that of V3+ increase linearly with the logarithm of capacitance and carbonyl group density. Kinetic current is calculated from the charge transfer coefficient and reaction rate constant, and correlated to the surface properties. For VO2+ to VO2+ reaction, slightly stronger relationship is observed for kinetic current vs logarithm of carbonyl group density than that vs the logarithm of capacitance and carboxylic group. For the V3+ to V2+ reaction, weak relationship between kinetic current and all the 3 properties are found.http://www.sciencedirect.com/science/article/pii/S2949821X25000717Vanadium redox flow batteryCarbon electrodesVO2+/VO2+ reaction kineticsV3+/V2+ reaction kineticsDiffusion coefficientElectrode capacitance
spellingShingle Chaojie Song
Roberto Neagu
Khalid Fatih
A study of VO2+/VO2+ and V3+/V2+ reactions on carbon-based electrodes – correlating reaction kinetics to electrode surface properties
Next Energy
Vanadium redox flow battery
Carbon electrodes
VO2+/VO2+ reaction kinetics
V3+/V2+ reaction kinetics
Diffusion coefficient
Electrode capacitance
title A study of VO2+/VO2+ and V3+/V2+ reactions on carbon-based electrodes – correlating reaction kinetics to electrode surface properties
title_full A study of VO2+/VO2+ and V3+/V2+ reactions on carbon-based electrodes – correlating reaction kinetics to electrode surface properties
title_fullStr A study of VO2+/VO2+ and V3+/V2+ reactions on carbon-based electrodes – correlating reaction kinetics to electrode surface properties
title_full_unstemmed A study of VO2+/VO2+ and V3+/V2+ reactions on carbon-based electrodes – correlating reaction kinetics to electrode surface properties
title_short A study of VO2+/VO2+ and V3+/V2+ reactions on carbon-based electrodes – correlating reaction kinetics to electrode surface properties
title_sort study of vo2 vo2 and v3 v2 reactions on carbon based electrodes correlating reaction kinetics to electrode surface properties
topic Vanadium redox flow battery
Carbon electrodes
VO2+/VO2+ reaction kinetics
V3+/V2+ reaction kinetics
Diffusion coefficient
Electrode capacitance
url http://www.sciencedirect.com/science/article/pii/S2949821X25000717
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