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Yin, Qiyi; Brandon, Nigel P.; Kelsall, G. H.

doi:10.1023/a:1004052419708

Cited by 15 publications

(4 citation statements)

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“…13,14 For carbon felt electrodes, values of up to 1.9 × 10 −3 mAcm −2 (Tafel slope of 320 mV) have been observed. 15 Nevertheless, parasitic hydrogen evolution at the negative electrode remains an issue for the long-term operation of flow batteries relying on acidic electrolyte solutions such as iron-chromium (E 0 of Cr 2+ /Cr 3+ = −0.41 V) [16][17][18] and all-vanadium (E 0 of V 2+ /V 3+ = −0.26 V) [19][20][21] types. Mitigation strategies comprise the use of inhibitors such as lead 16,18 or bismuth, 22,23 avoiding states of charge greater than 0.85 or the use of electrolyte rebalancing devices.…”

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confidence: 99%

Parasitic Hydrogen Evolution at Different Carbon Fiber Electrodes in Vanadium Redox Flow Batteries

Schweiss

Pritzl

Meiser

2016

J. Electrochem. Soc.

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Carbon fiber-based fabrics such as felts, cloths or papers are porous electrode materials that are widely used in redox flow batteries. This study investigates the effect of the carbon fiber properties on hydrogen evolution at the negative electrode, which occurs as an important side reaction in redox flow batteries employing acidic electrolytes. The lowest hydrogen evolution rate was observed at carbon fibers with a high content of graphitic domains which have been subjected to surface oxidation pre-treatment. By contrast, felt materials consisting of fibers with a largely amorphous character produce elevated amounts of hydrogen during battery charging. Differences between rayon-and polyacrylonitrile (PAN)-derived carbon fibers point toward the important role of nitrogen species. © The Author(s) 2016. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. [DOI: 10.1149/2.1281609jes] All rights reserved. Redox flow batteries are regarded as promising candidates for large-scale electrochemical storage systems for energy generated from fluctuating sources such as wind farms or photovoltaic systems.1-5 One of their widely acclaimed features is their inherent safety. Among other aspects, this is owing to the fact that the active masses consist of rather dilute, aqueous solutions of redox species (typically 1.5 to 3 molar) which are continuously circulated through an electrochemical reactor during operation. Consequently, only a small fraction of the redox species is present at any given time in the electrochemically active area, while the major part remains in electrolyte tanks, where it acts as a powerful thermal buffer.The obvious drawback of the aqueous cell chemistry is the relatively small electrochemical window, which is limited by the onset of the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Since common electrolytes contain strong acids with concentrations of up to 4 moles per liter in order to provide high ionic conductivity, the electrochemical window is reduced even further.Three-dimensional porous carbon electrodes such as felts, which are commonly manufactured from rayon (cellulose) or polyacrylonitrile (PAN) precursors, are well suited for these batteries since they come at a low cost, have a large surface area and exhibit sufficiently large overpotentials against hydrogen and oxygen evolution. [6][7][8][9][10][11] In the literature they are widely referred to as 'graphite' felts as they are processed at high temperatures similar to those used in the manufacturing of synthetic graphite. The fraction of crystalline domains, however, amounts to less than 50% 10 and the crystallographic d...

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mentioning

confidence: 99%

Parasitic Hydrogen Evolution at Different Carbon Fiber Electrodes in Vanadium Redox Flow Batteries

Schweiss

Pritzl

Meiser

2016

J. Electrochem. Soc.

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“…This implies that a higher cathodic activation energy is required to break the bonds and release molecular H 2 . 25 However HCOOH has shown a strong redox interaction with stainless steel electrode for both forward and reverse scans. There is one strong peak at the high positive potential (0.8 to 1.1 V vs. Ag/AgCl, sat.…”

Section: Resultsmentioning

confidence: 99%

Novel V(III) Compound, V(OH)(HCOO)₂: Electrochemical Synthesis, Characterization and Electroreduction Behavior on Suitable Electrodes

Bairwa

Mal

Naik

2014

J. Electrochem. Soc.

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Novel V(III) compound, V(OH)(HCOO) 2 has been synthesized by controlled current electrolysis route. V(OH)(HCOO) 2 precipitation during electrolysis was found to depend on both pH and concentration of V(III) in solution. It is an ionic V(III) compound with mild associated organic anion. The compound readily dissolves in pure water but subsequently precipitates out as polymer depending upon concentration and aging duration. However a stable aqueous solution with significantly high V(III) concentration could be prepared from it by adding a suitable complexing agent like nitrilotriacetic acid (NTA) and citric acid. These complex formulations will have potential application for nuclear power plant application and vanadium redox batteries. Electrochemical evaluation of the reduction characteristics of the compound on glassy carbon and stainless steel electrodes has established the varying effect of free acid at these surfaces. Part consumption of current for proton reduction on stainless steel electrodes and blocking of active sites by H + adsorption on carbon surfaces was observed. Thus, a high surface area carbon based electrodes will be better suited for high current efficiency during vanadous solution preparation by electroreduction while stainless steel electrodes may be used for efficient hydrogen generation from organic acids.Strong reducing agents are required in various fields ranging from energy storage, 1,2 analysis 3 to synthesis. 4 Strong reducing agents with favorable material compatibility behavior are also required for dissolution of various iron (III) oxides formed on primary heat transport system of water cooled nuclear power reactors. 5 These oxides are primary constituents of the corrosion products generated under hightemperature hydrothermal conditions. In the primary heat transport system, the solubilized/suspended corrosion products get activated as they pass through the reactor core and deposit at various locations based on their solubility at a particular temperature and water chemistry regime. 6 Hence, periodic decontamination procedure by means of chemical dissolution of the outer oxide layer of the structural surfaces is required to control the radiation field build up. 7 This involves reducing ferric ion in the oxide lattice to destabilize the oxide and subsequently complexing the dissolved metal ions with a proper ligand under favorable pH conditions. 8,9 Thus, the decontamination formulation is a mixture of a strong reducing agent, a suitable complexing agent and a pH maintaining agent. 10 Low oxidation state ions of chromium and vanadium namely Cr(II) and V(II) are suitable reducing agents for the purpose. 11 However, Cr(II) being highly unstable in aqueous media leaves V(II) as the practically applicable option for decontamination. The general corrosion rate for the austenitic materials in V(II) based formulations has been found to be less than 0.1 μm/h which is quite low for such applications. 8 While simple iron oxides like Fe 3 O 4 , γ-Fe 2 O 3 , FeOOH and α-Fe 2 O 3 etc., can be eff...

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“…The use of the following commercially available electrode materials is reported in the literature: pencil lead [1][2][3]; spectral [4,5], pyrolitic [6], and felt [7] graphites; carbon glass ceramic [8][9][10]; nonwoven graphite films [11]; carbon film resistors; and switches [12][13][14][15][16]. In most cases, electrodes of these materials are modified by metal films (mercury, copper, and bismuth), molecularly imprinted TiO 2 [17].…”

Section: Graphitized Carbon and Composite Electrodesmentioning

confidence: 99%

Modified carbon-containing electrodes in stripping voltammetry of metals. Part II. Composite and microelectrodes

Stozhko

Малахова

Fyodorov

et al. 2007

J Solid State Electrochem

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The second part of the review, which covers modified carbon-containing electrodes, describes composite and microelectrodes. Electrodes made of commercial and laboratory carbon-containing composite materials are discussed. Impregnated and thick-film electrodes and microelectrodes made of carbon fibers form a separate group. Various modifiers and methods of electrode modification are presented. Prospects for the future development of solid-state modified electrodes are considered. [12][13][14][15][16]. In most cases, electrodes of these materials are modified by metal films (mercury, copper, and bismuth), molecularly imprinted TiO 2 [17]. The occurrence in the last decade of new types of carbon materials "from carbon nanotubes to edge plane pyrolytic graphite" [18,19] has significantly changed the scope and sensitivity of electroanalytical methods for the measurement of diverse targets from metals ions to biological markers. Investigators considered in detail electrochemical characteristics [20] and practical use [21] of the "edge" plane pyrolytic graphite, which proved to have a wider interval of working potentials and a low detection limit as compared to those of the basal pyrolytic graphite and GC. For example, in situ bismuth film modified edge plane pyrolytic graphite electrode was successfully applied to the ultra trace simultaneous determination of cadmium(II) and lead(II) with detection limit 5.5·10 −10 and 4·10 −10 M, respectively [22].Synthetic diamonds (nitrogen-[23, 24] and boron-doped ) have come into use quite recently for electrochemical measurements. In particular, a gold-coated, borondoped, diamond thin-film electrode was used for total inorganic arsenic detection in real water samples [50]. Unlike properties of other carbon materials, which are widely used in electroanalysis, properties of synthetic diamonds became the subject of comprehensive study just about 10 years ago. The research was hindered by two circumstances: shortage of the material and the absence of conduction. The situation radically changed with the advent of highly efficient methods for growing of polycrystalline diamond compounds.A more efficient separation, accumulation, and determination of components is achieved with electrodes of composite materials made of graphite, carbon, glassy carbon, or diamond powders and binders such as paraffin, epoxy resins, methacrylate, silicon, styrene-acrylonitrile copolymer, polyester, and silica gel. The reviews [51][52][53][54] deal with properties and applications of various composite J Solid State Electrochem

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Untitled

Cited by 15 publications

References 28 publications

Parasitic Hydrogen Evolution at Different Carbon Fiber Electrodes in Vanadium Redox Flow Batteries

Parasitic Hydrogen Evolution at Different Carbon Fiber Electrodes in Vanadium Redox Flow Batteries

Novel V(III) Compound, V(OH)(HCOO)₂: Electrochemical Synthesis, Characterization and Electroreduction Behavior on Suitable Electrodes

Modified carbon-containing electrodes in stripping voltammetry of metals. Part II. Composite and microelectrodes

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Untitled

Cited by 15 publications

References 28 publications

Parasitic Hydrogen Evolution at Different Carbon Fiber Electrodes in Vanadium Redox Flow Batteries

Parasitic Hydrogen Evolution at Different Carbon Fiber Electrodes in Vanadium Redox Flow Batteries

Novel V(III) Compound, V(OH)(HCOO)2: Electrochemical Synthesis, Characterization and Electroreduction Behavior on Suitable Electrodes

Modified carbon-containing electrodes in stripping voltammetry of metals. Part II. Composite and microelectrodes

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Novel V(III) Compound, V(OH)(HCOO)₂: Electrochemical Synthesis, Characterization and Electroreduction Behavior on Suitable Electrodes