Electron transfer kinetics of the – Reaction on multi-walled carbon nanotubes

Friedl, J.; Bauer, Christoph; Rinaldi, Ali; Stimming, Ulrich

doi:10.1016/j.carbon.2013.06.076

Cited by 121 publications

(158 citation statements)

References 42 publications

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“…These treatments often have the effect of oxidizing or reducing the surface, and the influence of surface oxygen species on electrochemical kinetics at carbon electrodes is recognized, 22,[57][58][59][60] although often not well understood. Thermal [45][46][47][48][49] and chemical 36,40,43,44 treatments of electrodes for VFBs have been tested on a range of carbon-based electrodes and, in general, these treatments result in higher activities of the electrode toward the vanadium redox reactions. There are also a number of reports of the effect of electrochemical treatment of electrodes.…”

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confidence: 99%

Electrode Kinetics of Vanadium Flow Batteries: Contrasting Responses of V^II-V^IIIand V^IV-V^Vto Electrochemical Pretreatment of Carbon

Bourke

Miller

Lynch

et al. 2015

J. Electrochem. Soc.

105

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Electrochemical impedance spectroscopy and cyclic voltammetry were used to investigate the electrode kinetics of V II -V III and V IV -V V in H 2 SO 4 on glassy carbon, carbon paper, carbon xerogel, and carbon fibers. It was shown that, for all carbon materials investigated, the kinetics of V II -V III is enhanced by anodic, and inhibited by cathodic, treatment of the electrode; in contrast, the kinetics of V IV -V V is inhibited by anodic, and enhanced by cathodic, treatment. The potential region for each of these effects varied only slightly with carbon material. Rate constants were always greater for V IV -V V than for V II -V III except when anodized electrodes were compared, which may explain discrepancies in the literature. The observed effects are attributed to oxygen-containing functional-groups on the electrode surface. The considerable differences between the potentials at which enhancement of V II -V III and inhibition of V IV -V V occur indicates that they do not correspond to a common oxidized state of the electrode. Likewise inhibition of V II -V III and enhancement of V IV -V V do not correspond to a common reduced state of the electrode. It is possible that enhancement of both V II -V III and V IV -V V is due to the same (active) state of the electrode. There is considerable interest in vanadium flow batteries (VFBs), also known as vanadium redox flow batteries (VRFBs or VRBs), for storage of electrical energy particularly in conjunction with renewable energy sources such as wind and solar. [1][2][3][4][5][6] Active areas of research include cell design and modelling, [7][8][9] performance and state-of-charge monitoring, 10-16 coulombic and energy efficiencies, 5,17,18 electrolytes, [11][12][13][14][15][16]19,20 membranes, 4,21 and electrodes. Cells typically have porous carbon electrodes and electrode performance can depend strongly on electrode treatment. Various electrochemical, 22-27,36-41 chemical, 36,40,43,44 and thermal [45][46][47][48][49] treatments have been reported. These treatments often have the effect of oxidizing or reducing the surface, and the influence of surface oxygen species on electrochemical kinetics at carbon electrodes is recognized, 22,57-60 although often not well understood. Thermal 45-49 and chemical 36,40,43,44 treatments of electrodes for VFBs have been tested on a range of carbon-based electrodes and, in general, these treatments result in higher activities of the electrode toward the vanadium redox reactions. There are also a number of reports of the effect of electrochemical treatment of electrodes. Anodic treatment of carbon felt was reported 22,36 to cause a decrease in the kinetic rates of the V IV -V V redox couple. In contrast, there are also reports of enhancement of V IV -V V kinetics after electrochemical oxidation [38][39][40][41] (of graphite and carbon felt electrodes) and of V II -V III kinetics after potential cycling 61 (of highly-oriented-pyrolytic-graphite and glassy carbon electrodes). However, in considering the effects of anodization on a c...

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mentioning

confidence: 99%

Electrode Kinetics of Vanadium Flow Batteries: Contrasting Responses of V^II-V^IIIand V^IV-V^Vto Electrochemical Pretreatment of Carbon

Bourke

Miller

Lynch

et al. 2015

J. Electrochem. Soc.

105

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“…The kinetics of both the V II /V III and V IV /V V redox couples have been studied for a range of different carbon materials using a variety of techniques and it is clear that the kinetic rates depend strongly both on the type of carbon used and on the preparation of the electrode surface. 31,[35][36][37][38] Generally, the kinetics are found to be faster for V IV [17][18][19]21 and inhibition of V IV /V V electrode kinetics 17-21 by anodic treatment. In this paper we report detailed results on the effects of both anodic and cathodic treatment on the kinetics of the V IV /V V couple at carbon electrodes (glassy carbon, graphite, carbon paper, reticulated vitreous carbon (RVC), and carbon fibers).…”

mentioning

confidence: 99%

Effect of Cathodic and Anodic Treatments of Carbon on the Electrode Kinetics of V^IV/V^VOxidation-Reduction

Bourke¹,

Miller²,

Lynch³

et al. 2015

J. Electrochem. Soc.

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Cyclic voltammetry and electrochemical impedance spectroscopy were used to examine several types of carbon electrodes in V IV /V V in H 2 SO 4 . The materials investigated included glassy carbon, graphite, carbon paper, reticulated vitreous carbon and carbon fibers. In all cases the electrode kinetics of the V IV /V V oxidation-reduction reactions are enhanced by cathodic treatment of the electrode and inhibited by anodic treatment. Pronounced activation typically occurs at potentials more negative than +0.1 V (vs. Hg/Hg 2 SO 4 ); the effect begins to saturate at about -0.6 V. Pronounced deactivation typically occurs at potentials more positive than +0.7 V. Both activation and deactivation occur rapidly during the first ∼10 s at the most negative and most positive potentials, respectively. The activation effect saturates quickly at the most negative potentials but the deactivation effect does not saturate on the time scales investigated. There is a considerable shift (∼1.1 V) between the potentials for activation and deactivation. Activated electrodes showed no significant loss of activity after standing in the electrolyte for 3 weeks; deactivated electrodes regained about 50% of their activity. The activation and deactivation effects were observed regardless of whether vanadium was present in the electrolyte and are attributed to oxygen-containing functional groups on the electrode surface. All-Vanadium Flow Batteries (VFBs) are a promising technology to meet energy storage requirements for large scale and remote area applications.1-6 Like other flow battery systems the VFB is an electrochemical device that converts electrical energy to chemical energy which is stored in the electrolyte. Typical cells have carbon felt electrodes separated by a proton exchange membrane. The catholyte and the anolyte are circulated through the electrodes from reservoirs. Both electrolytes are highly acidic, typically 3 mol dm A variety of electrode treatments have been reported, including electrochemical, 17-28 chemical, 22,23,27,29,30 and thermal 31-34 treatments. These treatments often have the effect of oxidizing or reducing the surface and the influence of surface oxygen species on the performance of carbon electrodes is recognized, 50-53 although often not well understood.In order to better understand and improve the performance of VFB electrodes, it is important to investigate the electrode kinetics. The kinetics of both the V II /V III and V IV /V V redox couples have been studied for a range of different carbon materials using a variety of techniques and it is clear that the kinetic rates depend strongly both on the type of carbon used and on the preparation of the electrode surface. 31,[35][36][37][38] Generally, the kinetics are found to be faster for V IV [17][18][19]21 and inhibition of V IV /V V electrode kinetics 17-21 by anodic treatment. In this paper we report detailed results on the effects of both anodic and cathodic treatment on the kinetics of the V IV /V V couple at carbon electrodes (glassy carbon, gra...

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“…It is known that the positive electrode reactions are slower and more complicated than that of [V] 3+ /[V] 2+ redox couples (negative electrode), meaning that the former is the determining reaction [3]. Recently, MWCNTs has been introduced as a new positive electrode material for VRFBs because of its large reactive surface area, high stability in acidic solutions and relatively low cost [5][6][7][8]. Recently, MWCNTs has been introduced as a new positive electrode material for VRFBs because of its large reactive surface area, high stability in acidic solutions and relatively low cost [5][6][7][8].…”

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confidence: 99%

“…Recently, MWCNTs has been introduced as a new positive electrode material for VRFBs because of its large reactive surface area, high stability in acidic solutions and relatively low cost [5][6][7][8]. [5]. [5].…”

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RuO₂/MWCNT/ stainless steel mesh as a novel positive electrode in vanadium redox flow batteries

Gobal

Faraji

2015

RSC Adv.

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The present work describes the preparation and electrochemical characterization of RuO2/MWCNT/Stainless Steel Mesh (SSM) electrode as compared with a MWCNT/SSM electrode in the positive half-cell of a Vanadium Redox Flow Battery (VRFB). The electrochemical characterization of prepared electrode was carried out using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge procedures. The electrochemical activity of MWCNT/SSM modified with RuO2 as positive electrode in a VRFB was notably improved. The RuO2-included electrodes demonstrated high peak current ratio, small peak potential difference and high electron transfer rate constant, confirming excellent electro-catalytic activity and reversibility. These good electrochemical results, together with the long term stability of the prepared electrode, represent a significant step forward in the development of highly effective positive electrode materials for VRFBs. IntroductionAmong a wide range of energy storage technologies, redox flow batteries (RFB) offer several unique advantages, including the system scalability, long cycle life, and high energy efficiency [1]. RFBs are electrochemical energy storage devices where the energy is stored and converted through chemical changes of species dissolved in a working fluid. Among various kinds of RFB, vanadium RFB (VRFB) consisting of [VO] 2+ /[VO 2 ] + redox couples in the positive electrode and [V] 3+ /[V] +2

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Electron transfer kinetics of the – Reaction on multi-walled carbon nanotubes

Cited by 121 publications

References 42 publications

Electrode Kinetics of Vanadium Flow Batteries: Contrasting Responses of V^II-V^IIIand V^IV-V^Vto Electrochemical Pretreatment of Carbon

Electrode Kinetics of Vanadium Flow Batteries: Contrasting Responses of V^II-V^IIIand V^IV-V^Vto Electrochemical Pretreatment of Carbon

Effect of Cathodic and Anodic Treatments of Carbon on the Electrode Kinetics of V^IV/V^VOxidation-Reduction

RuO₂/MWCNT/ stainless steel mesh as a novel positive electrode in vanadium redox flow batteries

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Electron transfer kinetics of the – Reaction on multi-walled carbon nanotubes

Cited by 121 publications

References 42 publications

Electrode Kinetics of Vanadium Flow Batteries: Contrasting Responses of VII-VIIIand VIV-VVto Electrochemical Pretreatment of Carbon

Electrode Kinetics of Vanadium Flow Batteries: Contrasting Responses of VII-VIIIand VIV-VVto Electrochemical Pretreatment of Carbon

Effect of Cathodic and Anodic Treatments of Carbon on the Electrode Kinetics of VIV/VVOxidation-Reduction

RuO2/MWCNT/ stainless steel mesh as a novel positive electrode in vanadium redox flow batteries

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Product

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Electrode Kinetics of Vanadium Flow Batteries: Contrasting Responses of V^II-V^IIIand V^IV-V^Vto Electrochemical Pretreatment of Carbon

Electrode Kinetics of Vanadium Flow Batteries: Contrasting Responses of V^II-V^IIIand V^IV-V^Vto Electrochemical Pretreatment of Carbon

Effect of Cathodic and Anodic Treatments of Carbon on the Electrode Kinetics of V^IV/V^VOxidation-Reduction

RuO₂/MWCNT/ stainless steel mesh as a novel positive electrode in vanadium redox flow batteries