Facile synthesis of highly porous N-doped CNTs/Fe3C and its electrochemical properties

RSC Advances ◽  
2016 ◽  
Vol 6 (50) ◽  
pp. 44013-44018 ◽  
Author(s):  
Yanzhong Wang ◽  
Guoxiang Zhang ◽  
Guiwu Liu ◽  
Wei Liu ◽  
Huiyu Chen ◽  
...  
Keyword(s):  
Specific Surface ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Capacitance ◽  
Large Specific Surface Area ◽  
Facile Synthesis ◽  
Highly Porous

Porous N-doped CNTs/Fe3C was synthesized by a facile method. N-doped CNTs/Fe3C possesses the large specific surface area up to 1021.26 m2g−1. It exhibits a high specific capacitance of 181 F g−1at 0.1 A g−1and excellent capacitance rate.

Rational synthesis of graphitic porous carbon with high content nitrogen doping via ultra-fast pyrolysis of ZIF-8 for electrochemical capacitor with enhanced performance

2019 ◽  
Vol 12 (06) ◽  
pp. 1951004
Author(s):  
Tie Gao ◽  
Haibo Li
Keyword(s):  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rate Capability ◽  
Total Pore Volume ◽  
High Specific Capacitance ◽  
Superior Performance ◽  
Large Specific Surface Area ◽  
Average Pore

In this work, we proposed an effective strategy to prepare nitrogen-doped popcorn-like porous carbons (NPPCs) via ultra-fast carbonization of zeolitic immidazolate frameworks (ZIFs-8), where the ZIFs-8 acted as carbon precursor as well as the template. The obtained NPPCs possess popcorn-like morphology with large specific surface area of 1243[Formula: see text]m2/g, total pore volume of 1.48[Formula: see text]cm3/g and high nitrogen content. Remarkably, the average pore diameter of NPPCs was 4.72[Formula: see text]nm, indicating the presence of amount substantial mesopores. As the electrode of supercapacitor, the NPPCs revealed a relatively high specific capacitance of 610.4[Formula: see text]F/g in KOH (6[Formula: see text]mol/L) at 5[Formula: see text]mV/s. Even the scan rate was increased to 50[Formula: see text]mV/s, an impressive capacity of 424.8[Formula: see text]F/g can be achieved, suggesting good rate capability. Besides, it exhibited outstanding cycling stability with 93% of specific capacitance retention after 10,000 GCD cycles. Moreover, the NPPCs electrode demonstrated high electrochemical performance and stability by designing the coin-type and flexible supercapacitor. The large specific surface area, abundant accessible mesoporosity and novel nanostructure are account for the superior performance.

Modified polyacrylonitrile-based activated carbon fibers applied in supercapacitor

2016 ◽  
Vol 45 (3) ◽  
pp. 164-171 ◽  
Author(s):  
Linjie Su ◽  
Bohong Li ◽  
Dongyu Zhao ◽  
Chuanli Qin ◽  
Zheng Jin
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
Electrode Material ◽  
High Specific Capacitance ◽  
Activated Carbon Fibers ◽  
Content Type

Purpose The purpose of this paper is to prepare a new modified activated carbon fibers (ACFs) of high specific capacitance used for electrode material of supercapacitor. Design/methodology/approach In this study, the specific capacitance of ACF was significantly increased by using the phenolic resin microspheres and melamine as modifiers to prepare modified PAN-based activated carbon fibers (MACFs) via electrospinning, pre-oxidation and carbonization. The symmetrical supercapacitor (using MACF as electrode) and hybrid supercapacitor (using MACF and activated carbon as electrodes) were tested in term of electrochemical properties by cyclic voltammetry, AC impedance and cycle stability test. Findings It was found that the specific capacitance value of the modified fibers were increased to 167 Fg-1 by adding modifiers (i.e. 20 wt.% microspheres and 15 wt.% melamine) compared to that of unmodified fibers (86.17 Fg-1). Specific capacitance of modified electrode material had little degradation over 10,000 cycles. This result can be attributed to that the modifiers embedded into the fibers changed the original morphology and enhanced the specific surface area of the fibers. Originality/value The modified ACFs in our study had high specific surface area and significantly high specific capacitance, which can be applied as efficient and environmental absorbent, and advanced electrode material of supercapacitor.

Bead chain structure RFC/ACF by electrospinning for supercapacitors

2019 ◽  
Vol 48 (5) ◽  
pp. 439-448
Author(s):  
Lei Guo ◽  
Lien Zhu ◽  
Lei Ma ◽  
Jian Zhang ◽  
QiuYu Meng ◽  
...  
Keyword(s):  
Composite Material ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
High Specific Capacitance ◽  
Chain Structure ◽  
Cycle Stability ◽  
Content Type

Purpose The purpose of this paper is to prepare a spherical modifier-modified activated carbon fiber of high specific capacitance intended for electrode materials of supercapacitor. Design/methodology/approach In this study, phenolic-based microspheres are taken as modifiers to prepare PAN-based fiber composites by electrospinning, pre-oxidation and carbonization. Pearl-chain structures appear in RFC/ACF composites, and pure polyacrylonitrile fibers show a dense network. The shape and cross-linking degree are large. After the addition of the phenolic-based microspheres, the composite material exhibits a layered pearlite chain structure with a large porosity, and the RFC/ACF composite material is derived because of the existence of a large number of bead chain structures in the composite material. The density increases, the volume declines and the mass after being assembled into a supercapacitor as a positive electrode material decreases. The specific surface area of RFC/ACF composites is increased as compared to pure fibers. The increase in specific surface area could facilitate the diffusion of electrolyte ions in the material. Owing to the large number of bead chains, plenty of pore channels are provided for the diffusion of electrolyte ions, which is conducive to enhancing the electrochemical performance of the composite and improving the RFC/ACF composite and the specific capacitance of the material. The methods of electrochemical testing on symmetric supercapacitors (as positive electrodes) are three-electrode cyclic voltammetry, alternating current impedance and cycle stability. Findings The specific capacitance value of the composite material was found to be 389.2 F/g, and the specific capacitance of the electrode operating at a higher current density of 20 mA/cm2 was 11.87 F/g (the amount of the microsphere modifier added was 0.3 g). Using this material as a positive electrode to assemble into asymmetrical supercapacitor, after 2,000 cycles, the specific capacitance retention rate was 87.46 per cent, indicating excellent cycle stability performance. This result can be attributed to the fact that the modifier embedded in the fiber changes the porosity between the fibers, while improving the utilization of the carbon fibers and making it easier for electrolyte ions to enter the interior of the composites, thereby increasing the capacitance of the composites. Originality/value The modified PAN-based activated carbon fibers in the study had high specific surface area and significantly high specific capacitance, which makes it applicable as an efficient and environment-friendly absorbent, as well as an advanced electrode material for supercapacitor.

Effect of Morphology of ZnCo2O4 Nanostructures on Electrochemical Performance

NANO ◽  
2016 ◽  
Vol 11 (08) ◽  
pp. 1650089 ◽  
Author(s):  
J. Y. Dong ◽  
N. Zhang ◽  
S. Y. Lin ◽  
T. T. Chen ◽  
M. Y. Zhang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Specific Surface ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Specific Surface Area ◽  
Nickel Foam ◽  
High Specific Surface Area ◽  
Active Materials

The ZnCo2O4 nanorods and nanosheets were grown on nickel foam by a facile and effective hydrothermal method, respectively. The effect of the morphologies of the nanostructures on electrochemical performance was investigated. Importantly, ZnCo2O4 nanorod electrodes with a high specific surface area exhibited a higher specific capacitance of 2457.4 F g[Formula: see text] at 2 A g[Formula: see text] and remarkable cycling stability with capacitance retention of 97.7% after 1000 cycles, which are superior to those of ZnCo2O4 nanosheet electrodes. Such a result is well explained. The investigation on the electrochemical properties of these two nanostructures as electrodes confirmed that the morphology of active materials has an important impact on electrochemical properties.

Architecture engineering of supercapacitor electrode materials

2016 ◽  
Vol 09 (01) ◽  
pp. 1640001 ◽  
Author(s):  
Kunfeng Chen ◽  
Gong Li ◽  
Dongfeng Xue
Keyword(s):  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
High Specific Capacitance ◽  
High Energy ◽  
Supercapacitor Electrode

The biggest challenge for today’s supercapacitor systems readily possessing high power density is their low energy density. Their electrode materials with controllable structure, specific surface area, electronic conductivity, and oxidation state, have long been highlighted. Architecture engineering of functional electrode materials toward powerful supercapacitor systems is becoming a big fashion in the community. The construction of ion-accessible tunnel structures can microscopically increase the specific capacitance and materials utilization; stiff 3D structures with high specific surface area can macroscopically assure high specific capacitance. Many exciting findings in electrode materials mainly focus on the construction of ice-folded graphene paper, in situ functionalized graphene, in situ crystallizing colloidal ionic particles and polymorphic metal oxides. This feature paper highlights some recent architecture engineering strategies toward high-energy supercapacitor electrode systems, including electric double-layer capacitance (EDLC) and pseudocapacitance.

scholarly journals Nanocomposite Materials Based on Electrochemically Synthesized Graphene Polymers: Molecular Architecture Strategies for Sensor Applications

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 149
Author(s):  
André Olean-Oliveira ◽  
Gilberto A. Oliveira Brito ◽  
Celso Xavier Cardoso ◽  
Marcos F. S. Teixeira
Keyword(s):  
Conducting Polymers ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrochemical Sensors ◽  
Structural Characteristics ◽  
Low Cost ◽  
Large Specific Surface Area ◽  
Molecular Architecture ◽  
Sensor Applications

The use of graphene and its derivatives in the development of electrochemical sensors has been growing in recent decades. Part of this success is due to the excellent characteristics of such materials, such as good electrical and mechanical properties and a large specific surface area. The formation of composites and nanocomposites with these two materials leads to better sensing performance compared to pure graphene and conductive polymers. The increased large specific surface area of the nanocomposites and the synergistic effect between graphene and conducting polymers is responsible for this interesting result. The most widely used methodologies for the synthesis of these materials are still based on chemical routes. However, electrochemical routes have emerged and are gaining space, affording advantages such as low cost and the promising possibility of modulation of the structural characteristics of composites. As a result, application in sensor devices can lead to increased sensitivity and decreased analysis cost. Thus, this review presents the main aspects for the construction of nanomaterials based on graphene oxide and conducting polymers, as well as the recent efforts made to apply this methodology in the development of sensors and biosensors.

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