Enhancing the specific capacitance of SrRuO3 and reduced graphene oxide in NaNO3, H3PO4 and KOH electrolytes

2018 ◽  
Vol 260 ◽  
pp. 738-747 ◽  
Author(s):  
Ahmed Galal ◽  
Hagar K. Hassan ◽  
Timo Jacob ◽  
Nada F. Atta
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Reduced Graphene

Hybrid Supercapacitors Based on Self-Assembled Electrochemical Deposition of Reduced Graphene Oxide/Polypyrrole Composite Electrodes

2021 ◽  
Vol 16 (6) ◽  
pp. 949-956
Author(s):  
Jun Ma ◽  
Junaid Ali Syed ◽  
Dongyun Su
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Electrochemical Deposition ◽  
High Energy ◽  
Carbon Cloth ◽  
Discharge Process ◽  
Rate Performance ◽  
Reduced Graphene ◽  
Self Assembled

Conductive polymers (CPs) have potential application to commercial energy storage because of their high electrochemical activity and low cost. However, an obstacle in developing CP-based supercapacitors is the degradation in their capacitance during the charge-discharge process that leads to poor rate performance. This study fabricates layers of a high-performance self-assembled polypyrrole/reduced graphene oxide (PPY/RGO) composite material on a carbon cloth through electrochemical deposition. The layered graphene improved the electrochemical properties of PPY. Carbon fiber rods were coated with the PPY/RGO composite layer, the thickness of which depends on the deposition time. Adequate capacitive behaviors were achieved by using 16 layers of polypyrrole/reduced graphene oxide, with a specific capacitance of 490 F g−1 (0.6 A g−1) and good rate performance. The results here provide a novel means of preparing graphene-based nanocomposites films for a variety of functions. A symmetric device was subsequently assembled by using electrodes featuring 16 layers of the polypyrrole/reduced graphene oxide composite. It yielded a specific capacitance of 205 F g−1 and a high energy density of 16.4 Wh kg−1. It also exhibited good cycle stability, with a capacitance retention rate of 85% for 5,000 cycles.

Modulation of oxygen functional groups and their influence on the supercapacitor performance of reduced graphene oxide

2020 ◽  
Vol 44 (44) ◽  
pp. 19022-19027
Author(s):  
Zegao Wang ◽  
Yuqing Wang ◽  
Xin Hao ◽  
Jingbo Liu ◽  
Yuanfu Chen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Functional Groups ◽  
Oxygen Functional Groups ◽  
Reduced Graphene ◽  
Supercapacitor Performance

Through tuning the oxygen function groups, it was demonstrated that the specific capacitance of reduced graphene oxide can increase from 136 F g−1 to 182 F g−1.

scholarly journals Dissected carbon nanotubes functionalized by 1-hydroxyanthraquinone for high-performance asymmetric supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48341-48353 ◽  
Author(s):  
Xia Yang ◽  
Yuying Yang ◽  
Quancai Zhang ◽  
Xiaotong Wang ◽  
Yufeng An ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
Covalent Modification ◽  
Asymmetric Supercapacitors ◽  
Reduced Graphene

1-Hydroxyanthraquinone (HAQ) is selected to functionalize the dissected carbon nanotubes (rDCNTs) with reduced graphene oxide layers through non-covalent modification. The composite achieves high specific capacitance and ultrahigh rate capability.

Facile Synthesis of Modified MnO2/Reduced Graphene Oxide Nanocomposites and their Application in Supercapacitors

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050099
Author(s):  
Lijun Chen ◽  
Hongfeng Yin ◽  
Yuchao Zhang ◽  
Huidong Xie
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrode Materials ◽  
Normal Pressure ◽  
X Ray ◽  
Assembly Method ◽  
Reduced Graphene

Herein, KH-550 was used as surface modifier to prepare modified MnO2/reduced graphene oxide (M-MnO2/rGO) composite electrode materials by utilizing electrostatic interaction at low temperature and normal pressure. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy were adopted to characterize the material’s phase, morphology, and valence state of elements. The electrochemical properties of the material were measured using a three-electrode system. The results indicate a decrease in the size of the modified MnO2 particles, and that they were uniformly distributed on the rGO sheets. The M-MnO2/rGO composite attained a specific capacitance of 326[Formula: see text]F[Formula: see text]g[Formula: see text] in a solution of 1[Formula: see text]mol[Formula: see text]L[Formula: see text] Na2SO4 at a current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text]. The specific capacitance of the material was 92.4% after 1000 cycles. The electrostatic self-assembly method effectively solved the problem of reducing the cycling stability while improving the specific capacitance of the composite materials, and further improved the possibility of applying MnO2/rGO in the field of supercapacitors.

Nitrogen-Enriched Reduced Graphene Oxide for High Performance Supercapacitor Electrode

2020 ◽  
Vol 20 (8) ◽  
pp. 4854-4859 ◽  
Author(s):  
Lei Chen ◽  
Xu Chen ◽  
Yaqiong Wen ◽  
Bixia Wang ◽  
Yangchen Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Electrode Material ◽  
High Performance ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Oxide Electrode ◽  
Reduced Graphene

Nitrogen-enriched reduced graphene oxide electrode material can be successfully prepared through a simple hydrothermal method. The morphology and microstructure of ready to use electrode material is measured by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). Physical characterizations revealed that nitrogen-enriched reduced graphene oxide electrode material possessed high specific surface area of 429.6 m2 · g−1, resulting in high utilization of electrode materials with electrolyte. Electrochemical performance of nitrogen-enriched reduced graphene oxide electrode was also investigated by cyclic voltammetry (CV), galvanostatic charge/discharge measurements and electrochemical impedance spectroscopy (EIS) in aqueous in 6 M KOH with a three-electrode system, which displayed a high specific capacitance about 223.5 F · g−1 at 1 mV · s−1. More importantly, nitrogenenriched reduced graphene oxide electrode exhibited outstanding stability with 100% coulombic efficiency and with no specific capacitance loss under 2 A · g−1 after 10000 cycles. The supercapacitive behaviors indicated that nitrogen-enriched reduced graphene oxide can be a used as a promising electrode for high-performance super-capacitors.

Facile Synthesis and Performance of Reduced Graphene Oxide/Cobalt Oxide Composite for Supercapacitor

2013 ◽  
Vol 785-786 ◽  
pp. 779-782
Author(s):  
Hong Juan Wang ◽  
Dong Zhou ◽  
Feng Peng ◽  
Hao Yu
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Cobalt Oxide ◽  
Current Density ◽  
Chemical Precipitation ◽  
Discharge Performance ◽  
Reduced Graphene ◽  
Subsequent Calcination ◽  
And Performance

A series of reduced graphene oxide/cobalt oxide composites (Co3O4/rGO)were fabricated via a chemical precipitation approach and subsequent calcination in Ar atmosphere. Experimental results show that Co3O4/rGO composite with 86 wt% of Co3O4 loading exhibits the optimum specific capacitance of 240 F g-1 in 6.0 M KOH electrolyte at the current density of 0.8 A g-1, excellent quick charge-discharge performance and outstanding cyclic stability with 2.3% of its specific capacitance increase after 2400 cycles at the current density of 8 A g-1 in GCD test, exhibiting significant potential of Co3O4 /rGO composite in the application of supercapacitors.

scholarly journals Development of New Carbon-Based Electrode Material from Oil Palm Waste-Derived Reduced Graphene Oxide and Its Capacitive Performance Evaluation

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Salisu Nasir ◽  
Mohd Zobir Hussein ◽  
Zulkarnain Zainal ◽  
Nor Azah Yusof
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Oil Palm ◽  
Palm Kernel ◽  
Graphene Oxides ◽  
Palm Kernel Shell ◽  
Reduced Graphene ◽  
Reduced Graphene Oxides ◽  
Carbon Based

This paper is an expansion of our previous work on the synthesis of graphene oxides and reduced graphene oxides from different kinds of oil palm waste-based feedstocks, namely, OPL (oil palm leaf), PKS (palm kernel shell), and EFB (empty fruit bunch). Here, the electrochemical measurements of the resulting reduced graphene oxides derived via mild-temperature annealing reduction of the graphene oxides were accomplished using cyclic voltammetry and galvanostatic charge/discharge processes. The findings put forward their promising features for supercapacitor applications. For instance, the reduced graphene oxide derived using EFB precursor (rGOEFB) which has a BET surface area of 117 m2 g-1 exhibits a specific capacitance of 688 F g−1 at an applied current density of 0.8 A g-1. This is higher than that observed for reduced graphene oxides derived from oil palm leaf (rGOOPL), palm kernel shell (rGOPKS), and the commercially acquired graphite (rGOCG), which possessed specific capacitance values of 632, 424, and 220 F g−1, respectively. It can be deduced that the specific capacitance of the reduced graphene oxide samples increases in the following order: (rGOCG) < (rGOPKS) < (rGOOPL) < (rGOEFB). In summary, these new classes of carbon-based nanomaterials could be applied as efficient electrode materials for supercapacitor application with potential good performance. With this novel green and sustainable approach, various carbon-based nanomaterials can be fabricated for a broad range of multifunctional applications.

scholarly journals Blotting Paper-Derived Activated Porous Carbon/Reduced Graphene Oxide Composite Electrodes for Supercapacitor Applications

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4625 ◽  
Author(s):  
Qinting Jiang ◽  
Dandan Liu ◽  
Bo Liu ◽  
Tong Zhou ◽  
Jin Zhou
Keyword(s):  
Graphene Oxide ◽  
Activated Carbon ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Low Cost ◽  
Chemical Activation ◽  
Scale Production ◽  
Composite Electrodes ◽  
Oxide Composite ◽  
Reduced Graphene

A facile strategy, engineered for low-cost mass production, to synthesize biomass-derived activated carbon/reduced graphene oxide composite electrodes (GBPCs) by one-pot carbonization of blotting papers containing graphene oxide (GO) and zinc chloride (ZnCl2) was proposed. Benefitting from the water absorption characteristic of blotting papers in which the voids between the celluloses can easily absorb the GO/ZnCl2 solution, the chemical activation and reduction of GO can synchronously achieve via one-step carbonization process. As a result, the GBPCs deliver a large specific surface area to accumulate charge. Simultaneously, it provides high conductivity for electron transfer. The symmetric supercapacitor assembled with the optimal GBPCs in 6 M KOH electrolyte exhibits an excellent specific capacitance of 204 F g−1 (0.2 A g−1), outstanding rate capability of 100 F g−1 (20 A g−1). Meanwhile, it still keeps 90% of the initial specific capacitance over 10,000 cycles. The readily available raw material, effective chemical activation, simple rGO additive, and resulting electrochemical properties hold out the promise of hope to achieve low-cost, green, and large-scale production of practical activated carbon composite materials for high-efficiency energy storage applications.

Activated Carbon Based Supercapacitors with a Reduced Graphene Oxide Additive: Preparation and Properties

2020 ◽  
Vol 20 (7) ◽  
pp. 4073-4083 ◽  
Author(s):  
Jia-Wei Wang ◽  
Wei-Ke Zhang ◽  
Chen Jiao ◽  
Fang-Yuan Su ◽  
Cheng-Meng Chen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Activated Carbon ◽  
Carbon Black ◽  
Pore Size Distribution ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Mesoporous Structure ◽  
Conductive Carbon Black ◽  
Reduced Graphene ◽  
Conductive Agent

We have successfully enhanced the performance of commercial supercapacitors that use Japan Kuraray 80F activated carbon and Super-P conductive carbon black as the conductive agent with reduced graphene oxide (rGO) additive. The ratios of conductive carbon black to rGO studied are 3:1, 5:1, 10:1, 15:1 and 1:0. The enhancement is most pronounced at 15:1, and the specific capacitance being 137.5 F g−1, which is a 23.8% improvement over the 1:0 control. The specific capacitance retention is 70.1% after 10000 cycles. The impedance resistance is also reduced to 1.5 Ω, which is 3.3 times lower than the 1:0 control. Additionally, the rGO additive does not alter the favorable pore size distribution of the primary matrix and successfully preserves its small mesoporous structure, which facilitates facile transport of electrolyte.

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