Study on the specific capacitance of an activated carbon cloth modified with reduced graphene oxide and polyaniline by cyclic voltammetry

2017 ◽  
Vol 92 ◽  
pp. 194-203 ◽  
Author(s):  
J. Fernández ◽  
J. Bonastre ◽  
J. Molina ◽  
A.I. del Río ◽  
F. Cases
2021 ◽  
Vol 16 (6) ◽  
pp. 949-956
Author(s):  
Jun Ma ◽  
Junaid Ali Syed ◽  
Dongyun Su

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.


Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4625 ◽  
Author(s):  
Qinting Jiang ◽  
Dandan Liu ◽  
Bo Liu ◽  
Tong Zhou ◽  
Jin Zhou

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.


2020 ◽  
Vol 20 (7) ◽  
pp. 4073-4083 ◽  
Author(s):  
Jia-Wei Wang ◽  
Wei-Ke Zhang ◽  
Chen Jiao ◽  
Fang-Yuan Su ◽  
Cheng-Meng Chen ◽  
...  

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.


2021 ◽  
Vol 63 (12) ◽  
pp. 1184-1190
Author(s):  
Yifan Cui ◽  
Rong Li ◽  
Liuqin Lai ◽  
Huimin Dai ◽  
Siyu Su ◽  
...  

Abstract The chemical reduction of graphene oxide is an effective method for the synthesis of reduced graphene oxide, having the obvious advantages of low cost and large scale applicability. Our work produced reduced graphene oxide through a simple water bath reduction approach using various reducing agents of N2H4 × H2O, NaBH4, Na2S2O3, HI, and a reference sample without reducing agent at the same reduction temperature and duration time, by which reduced graphene oxides represented as N-RGO, B-RGO, S-RGO, I-RGO, and RGO0 were fabricated. Subsequently, unbonded flexible electrodes based on carbon cloth were fabricated with the reduced graphene oxides mentioned above, whereupon the structure, morphology and electrochemical performance were characterized. The electrochemical results indicate that the order of specific capacitances is N-RGO > B-RGO > S-RGO > RGO0 > I-RGO, while I-RGO’s potential window is wider than that of the others. As a result, N-RGO displays the best electrochemical performance among all reduced graphene oxides, with a specific capacitance as high as 176.0 F × g-1 and 77.8 % of the initial specific capacitance maintained at a high current density of 20 A × g-1.


Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 18
Author(s):  
Sutthima Sriprasertsuk ◽  
John R. Varcoe ◽  
Carol Crean

Reduced graphene oxide (rGO) fibre electrodes and their ability to sense paracetamol (as model drug) were studied. rGO was electrodeposited onto carbon fibre by two different approaches: potentiostatic deposition and cyclic voltammetry (CV) in the presence of graphene oxide solution. Carbon fibre electrodes coated with rGO (after five CV cycles) could sense paracetamol with an oxidation peak at 0.62 V (vs. Ag/AgCl). The limit of detection of this fibre sensor was found to be 36.3 µM with a linear range of 50–500 µM of paracetamol (R2 = 0.9901).


2020 ◽  
Vol 44 (44) ◽  
pp. 19022-19027
Author(s):  
Zegao Wang ◽  
Yuqing Wang ◽  
Xin Hao ◽  
Jingbo Liu ◽  
Yuanfu Chen ◽  
...  

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.


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