The Temperature Role in the Manufacturing of an Electrode for Supercapacitors with Carbon Black and Graphene Oxide (original) (raw)
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With their relative ease of production and coupled strong surface functionality and electrical conductivity properties, graphene oxide (GO) and reduced graphene oxide (rGO) are exciting, yet overlooked, graphene-like additive prospects for activated carbon (AC) electrodes in supercapacitors. In this work, we incorporated small amounts of synthesized GO and rGO in AC electrodes via a simple mixing procedure to explore their effects. In addition to materials characterizations, symmetric supercapacitors were made from these electrodes and tested across current densities ranging from 0.1–10 A g−1 and across 10,000 additional charge-discharge cycles at 2 A g−1. Performance measurements indicate that GO and rGO enhance the rate resistance and capacity, respectively, of AC electrodes, but these effects are modest and do not prevent increases in internal resistance over the course of 10,000 cycles. The overall ineffectuality of GO and rGO is reasoned to be due to their isolation and infrequ...
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We investigated graphene like material named reduced graphene oxide (RGO) as an electrode material by employed graphene oxide (GO). Thin film of GO was prepared on the indium thin oxide (ITO) substrate by spin-coating method using varied concentration of GO that dispersed in water. In order to remove its oxygen contained, GO film was thermally reduced at 200 0 C for 1 hour. We used cyclic voltammetry to measure its CV characteristic and estimated its specific capacitance. We obtained the highest specific capacitance of 6.53 mF g −1 that measured from 4 mg ml-1 RGO thin film at scan rate 25 mVs-1 .
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The paper reports synthesis of graphene oxide (GO) using modified Hummer's method and its hydrothermal assisted reduction to produce reduced graphene oxide (rGO) for supercapacitor applications. Synthesized GO and rGO were characterized using Raman spectroscopy and their I d /I g ratio was found to be 0.94 and 0.87, respectively. Scanning Electron Microscopy (SEM) was also performed on samples for detailed surface morphology information. UV-Vis spectroscopy was employed to investigate optical properties. FT-IR spectroscopy was utilized to get the information of attached functional groups and electrochemical characterization (cyclic voltammetry) was used to test the charging discharging behavior of the material. The specific capacitance of synthesized rGO was found to be 105F/g.
SN applied sciences, 2020
Graphene-metal frameworks have been extensively studied and developed as electrode materials for next generation energy storage materials. Their high surface area and easily transformable structure enhances its specific capacitance characteristics. In the present study, graphene oxide (GO) was synthesized using Hummers method. Zinc oxide and copper oxide nanoparticles were incorporated in to the GO matrix to form mixed metal oxides. GO, GO-CuO and GO-ZnO were characterized using UV-Visible, FTIR, FT Raman spectroscopy, SEM and XRD to confirm their effective formation. The surface of the glassy carbon electrode was modified by drop casting with the samples on its surface and its electrochemical properties were studied. Cyclic Voltammetry studies were conducted at various scan rates in different electrolytes (KCl, H 2 SO 4 and Na 2 SO 4) and the characteristic curves were observed to be asymmetric in nature. GO-CuO exhibits the highest specific capacitance of 790 F/g at 5 mV/s in KCl. The specific capacitance of the modified electrodes was also measured using the Chronopotentiometry technique. GO-CuO nanocomposites show a maximum specific capacitance of 800 F/g at 1 A/g. The nanocomposites showed enhanced electrochemical behaviour of the nanocomposites when compared to pure GO. The nanocomposites also showed good cycling stability. The superior performance of the GO-CuO and GO-ZnO nanocomposite electrode renders it as a promising material for supercapacitors applications.
Lancet
Graphene nanosheets (GNs) dispersed with SnO2 nanoparticles loaded multiwalled carbon nanotubes (SnO2–MWCNTs) were investigated as electrode materials for supercapacitors. SnO2–MWCNTs were obtained by a chemical method followed by calcination. GNs/SnO2–MWCNTs nanocomposites were prepared by ultrasonication of the GNs and SnO2–MWCNTs. Electrochemical double layer capacitors were fabricated using the composite as the electrode material and aqueous KOH as the electrolyte. Electrochemical performance of the composite electrodes were compared to that of pure GNs electrodes and the results are discussed. Electrochemical measurements show that the maximum specific capacitance, power density and energy density obtained for supercapacitor using GNs/SnO2–MWCNTs nanocomposite electrodes were respectively 224 F g−1, 17.6 kW kg−1 and 31 Wh kg−1. The fabricated supercapacitor device exhibited excellent cycle life with ∼81% of the initial specific capacitance retained after 6000 cycles. The results suggest that the hybrid composite is a promising supercapacitor electrode material.► Graphene nanosheets (GNs) dispersed with SnO2 nanoparticles loaded multiwalled carbon nanotubes (SnO2–MWCNTs) as electrode materials for supercapacitors. ► A maximum specific capacitance of 224 F g−1, power density of 17.6 kW kg−1 and an energy density of 31 Wh kg−1. ► Excellent cycle life with ∼81–92% of the initial specific capacitance retained after 6000 cycles, depending on electrode type. ► Dispersion of SnO2–MWCNTs helps in the improvement of the capacitance properties of GNs. ► GNs/SnO2–MWCNTs is a promising supercapacitor electrode material for practical applications.