Graphite Oxide: An Interesting Candidate for Aqueous Supercapacitors

Lobato, Belén; Wendelbo, Rune; Barranco, Violeta; Centeno, Teresa A.

doi:10.1016/j.electacta.2014.10.095

Cited by 17 publications

(15 citation statements)

References 38 publications

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“…S3 †) and conrm the different electrochemical operation of the diverse graphene-related materials. 34 As reported elsewhere, 36 such outstanding surface-capacitance in F m À2 only reects the limitation of the standard N 2 adsorption at 77 K to probe the effective surface involved in the ions adsorption in this type of carbons made of expanded carbon layers. 7 briey summarizes the general trends in the capacitance of the products generated by direct oxidation of carbon nanobers and subsequent treatments (Fig.…”

Section: Performance As Supercapacitor Electrodesmentioning

confidence: 80%

Large-scale conversion of helical-ribbon carbon nanofibers to a variety of graphene-related materials

et al. 2016

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Helical-ribbon carbon nanofibers produced on an industrial scale were successfully converted in highly functionalized graphene nanoplatelets by using a slight modification of the Hummers oxidation method.The duration of the oxidative process severely affected the interlayer spacing in the resulting nanoplatelets and, consequently, they showed very different exfoliation behavior. Therefore, it was possible to obtain a variety of graphene-related products through their ultrasonication or thermal treatments such as exfoliation-reduction by flash-pyrolysis in air at temperatures between 400 and 1000 C or standard activation with CO 2 at 800 C. Detailed comparison of the functionalized carbon nanoplatelets, graphene oxides, reduced graphene oxides and activated carbon nanoplatelets reveals the wide spectrum of their properties with specific surface areas in the range of 4-500 m 2 g À1 , oxygen content from 38 to 5 wt% and different structural ordering. This study also underlines the impact of the structural, textural and chemical changes experienced by the carbon nanofibers along the various processes on the performance as supercapacitor electrodes. This preliminary study, based on cyclic voltammetry in 2 M H 2 SO 4 aqueous electrolyte, is a summary of the strengths and weaknesses of the different graphene-related materials for this application. The helical-ribbon carbon nanofibers displayed only 10 F g À1 , the capacitance of the functionalized graphene nanoplatelets greatly rose to 104 F g À1 with clear contributions from pseudocapacitance. Values around 100-120 F g À1 were found for the graphene oxides and activated graphene nanoplatelets although a marked resistive character is detected.Flash-pyrolysis at 1000 C leads to lower capacitance (79 F g À1 ) but much quicker charge propagation.Among all these materials, the lower-cost functionalized graphene nanoplatelets displayed the better behavior for aqueous supercapacitors.

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Section: Performance As Supercapacitor Electrodesmentioning

confidence: 80%

Large-scale conversion of helical-ribbon carbon nanofibers to a variety of graphene-related materials

et al. 2016

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“…Various correlations between the physico-chemical properties of carbons and the operation of the corresponding SCs have been proposed so far [14][15][16][17][18][19][20][21] by the assessment of a large variety of materials under the same experimental conditions [22]. They appear to be successful in most cases, but the behavior of certain carbons such as graphene-type materials cannot be explained within the general patterns found for a number of typical porous materials [23,24]. In this context, Wu et al [25], have reported the difficulties for assessing adequately the combined roles of surface area and surface functionalities in the performance of nanoporous carbons in supercapacitors.…”

Section: Introductionmentioning

confidence: 99%

The importance of electrode characterization to assess the supercapacitor performance of ordered mesoporous carbons

Sánchez-Sánchez

Centeno

Suárez-Garcı́a

et al. 2016

Microporous and Mesoporous Materials

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Carbon based-supercapacitors are widely used in numerous applications but the knowledge of the specific role of carbon features in their performance is still insufficient. The main aim of this work is to warn readers that the current interpretation of the device operation, mostly based on powdered carbon properties, may be misleading in certain cases and should be complemented with the physicochemical characterization of the corresponding electrodes. Ordered mesoporous carbons highly enriched in surface functionalities were prepared by carbonization of 3aminobenzoic acid into SBA-15 template. These carbons achieved a specific capacitance as high as 220 F/g in 2M H 2 SO 4 aqueous electrolyte. The pseudocapacitance contribution ranged between 35 and 70% of the overall capacitance. It was shown that the structural and textural changes underwent by these advanced carbons during their processing in form of electrodes prevented the full exploitation of their outstanding properties for high-power applications. This makes a difference regarding conventional, disordered activated carbons, which virtually preserve their structure during electrode preparation.

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“…15 A capacitance of up to 159 F g À1 in H 2 SO 4 and 82 F g À1 in (C 2 H 5 ) 4 NBF 4 /acetonitrile was reported for GO, 10 and it showed a much higher volumetric capacitance than the majority of other carbon materials, which is a key factor for the development of energy storage devices. A higher capacitance of up to 189 F g À1 was obtained with GO electrodes in a symmet-focused on the size effect of raw graphite on the electrochemical characteristics of GO for supercapacitors.…”

Section: -6mentioning

confidence: 99%

“…[7][8][9] Currently, there is a wide variety of carbon-based materials that have served as electrodes for supercapacitors, including activated carbons, carbon gels, carbon bers, carbon nanotubes, graphene, and graphene oxide (GO). 10 Among them, graphene has high electrical conductivity and a large theoretical surface area of 2670 m 2 g À1 , which make it an ideal electrode material of supercapacitors. However, there are a few shortcomings to the synthesis of high quality graphene:…”

Section: -6mentioning

confidence: 99%

“…The electrode was dried at 60 C in a vacuum oven for 24 h. Finally, the nickel foam coated with the active materials as the working electrode, a platinum foil as the counter electrode, a saturated calomel electrode as the reference electrode, and 6 M potassium hydroxide solution as electrolyte were used. Cyclic voltammetry (CV) was performed with a potential window from À0.8 V to 0 V at different scan rates (5,10,20,30, and 50 mV s À1 ). Galvanic cycling (GC) was carried out with a voltage from À0.7 V to 0 V at various current densities (0.1, 0.2, 0.5, 1, and 2 A g À1 ).…”

Section: Electrochemical Measurementsmentioning

confidence: 99%

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The importance of raw graphite size to the capacitive properties of graphene oxide

Xie

et al. 2016

RSC Adv.

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Carbon-based materials have been widely used in energy storage and conversion devices. Among them, graphene oxide (GO) holds much promise for supercapacitor applications due to its high-capacitance, low-cost, etc. Nevertheless, intrinsic characteristics related to the capacitive properties of GO are far from being fully understood. Little attention has been paid to the size effect of raw graphite on the electrochemical characteristics of GO. In order to investigate the relationship between raw graphite size and the capacitive properties of GO, electrochemical performances of GO, prepared from raw graphite of three different sizes using a modified Hummer's method, were compared. Experimental results indicated that the capacitance of a GO electrode was enhanced with the increasing size of the raw graphite. The GO electrode prepared with the largest size of raw graphite achieved a specific capacitance as high as 94.4 F g À1 at 0.1 A g À1 due to a medium-sized specific surface area and smaller charge transfer resistance. It is concluded that more attention should be paid to the prevention of agglomeration or even restacking of the graphene-based material after the heat drying of graphenebased solutions because of residual intercalated water molecules, which contribute to strong hydrogen bonding interactions between layers.

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Graphite Oxide: An Interesting Candidate for Aqueous Supercapacitors

Cited by 17 publications

References 38 publications

Large-scale conversion of helical-ribbon carbon nanofibers to a variety of graphene-related materials

Large-scale conversion of helical-ribbon carbon nanofibers to a variety of graphene-related materials

The importance of electrode characterization to assess the supercapacitor performance of ordered mesoporous carbons

The importance of raw graphite size to the capacitive properties of graphene oxide

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