scholarly journals Preparation of Network-Structured Carbon Nanofiber Mats Based on PAN Blends Using Electrospinning and Hot-Pressing Methods for Supercapacitor Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2447
Author(s):  
Min-Jung Ma ◽  
Jae-Gyoung Seong ◽  
Sivaprakasam Radhakrishnan ◽  
Tae-Hoon Ko ◽  
Byoung-Suhk Kim
Keyword(s):  
Specific Capacitance ◽  
Hot Pressing ◽  
Carbon Nanofiber ◽  
Molecular Weights ◽  
Good Energy ◽  
Asymmetric Hybrid ◽  
Set Up ◽  
Nanofiber Mats ◽  
Supercapacitor Applications ◽  
A Current

In this work, we prepared network-structured carbon nanofibers using polyacrylonitrile blends (PAN150 and PAN85) with different molecular weights (150,000 and 85,000 g mol−1) as precursors through electrospinning/hot-pressing methods and stabilization/carbonization processes. The obtained PAN150/PAN85 polymer nanofibers (PNFs; PNF-73, PNF-64 and PNF-55) with different weight ratios of 70/30, 60/40 and 50/50 (w/w) provided good mechanical and electrochemical properties due to the formation of physically bonded network structures between the blended PAN nanofibers during the hot-processing/stabilization processes. The resulting carbonized PNFs (cPNFs; cPNF-73, cPNF-64, and cPNF-55) were utilized as anode materials for supercapacitor applications. cPNF-73 exhibited a good specific capacitance of 689 F g−1 at 1 A g−1 in a three-electrode set-up compared to cPNF-64 (588 F g−1 at 1 A g−1) and cPNF-55 (343 F g−1 at 1 A g−1). In addition, an asymmetric hybrid cPNF-73//NiCo2O4 supercapacitor device also showed a good specific capacitance of 428 F g−1 at 1 A g−1 compared to cPNF-64 (400 F g−1 at 1 A g−1) and cPNF-55 (315 F g−1 at 1 A g−1). The cPNF-73-based device showed a good energy density of 1.74 W h kg−1 (0.38 W kg−1) as well as an excellent cyclic stability (83%) even after 2000 continuous charge–discharge cycles at a current density of 2 A g−1.

Facile Preparation of Commercial Bi2O3 Nanoparticle Decorated Activated Carbon for Pseudocapacitive Supercapacitor Applications

2021 ◽  
Author(s):  
Osman Üner ◽  
Naim Aslan ◽  
Akın Sarıoğlu ◽  
Fatih Semerci ◽  
Mumin Mehmet Koc
Keyword(s):  
Activated Carbon ◽  
Specific Capacitance ◽  
Bismuth Oxide ◽  
Weight Ratio ◽  
Carbon Composites ◽  
Active Carbons ◽  
Facile Preparation ◽  
Supercapacitor Applications ◽  
A Current ◽  
Maximum Specific Capacitance

Abstract In this work, a facile method to prepare commercial nano-Bi2O3/carbon composites with high pseudocapacitive properties was presented. The inorganic-organic composites synthesized by using commercial bismuth oxide and active carbon with different weight ratio. The composites were characterized using microscopic, spectroscopic, and diffractive methods. Our assessments confirmed that active carbons were successfully doped with commercial Bi2O3 nanoparticles with different dopant rates. The composites exhibited a maximum specific capacitance of 517 F/g at a current density of 1 A/g for 20% Bi2O3 nanoparticle doped activated carbon samples. Augmented discharging time was also achieved for increased Bi2O3 nanoparticle doping rate. Increased Bi2O3 dopant rate also increased the calculated specific capacitance.

scholarly journals An efficient electrode material for high performance solid-state hybrid supercapacitors based on a Cu/CuO/porous carbon nanofiber/TiO2 hybrid composite

2019 ◽  
Vol 10 ◽  
pp. 781-793 ◽  
Author(s):  
Mamta Sham Lal ◽  
Thirugnanam Lavanya ◽  
Sundara Ramaprabhu
Keyword(s):  
Solid State ◽  
Specific Capacitance ◽  
Current Density ◽  
Electrode Material ◽  
Porous Carbon ◽  
Carbon Nanofiber ◽  
High Energy ◽  
High Energy Density ◽  
Porous Carbon Nanofiber ◽  
A Current

A Cu/CuO/porous carbon nanofiber/TiO2 (Cu/CuO/PCNF/TiO2) composite uniformly covered with TiO2 nanoparticles was synthesized by electrospinning and a simple hydrothermal technique. The synthesized composite exhibits a unique morphology and excellent supercapacitive performance, including both electric double layer and pseudo-capacitance behavior. Electrochemical measurements were performed by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The highest specific capacitance value of 530 F g−1 at a current density of 1.5 A g−1 was obtained for the Cu/CuO/PCNF/TiO2 composite electrode in a three-electrode configuration. The solid-state hybrid supercapacitor (SSHSC) fabricated based on this composite exhibits a high specific capacitance value of 330 F g−1 at a current density of 1 A g−1 with 78.8% capacitance retention for up to 10,000 cycles. At the same time, a high energy density of 45.83 Wh kg−1 at a power density of 1.27 kW kg−1 was also realized. The developed electrode material provides new insight into ways to enhance the electrochemical properties of solid-state supercapacitors, based on the synergistic effect of porous carbon nanofibers, metal and metal oxide nanoparticles, which together open up new opportunities for energy storage and conversion applications.

scholarly journals A Hierarchical Architecture of Functionalized Polyaniline/Manganese Dioxide Composite with Stable-Enhanced Electrochemical Performance

2021 ◽  
Vol 5 (5) ◽  
pp. 129
Author(s):  
Yapeng Wang ◽  
Yanxiang Wang ◽  
Chengjuan Wang ◽  
Yongbo Wang
Keyword(s):  
Electrochemical Performance ◽  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Current Density ◽  
Electrode Materials ◽  
High Efficiency ◽  
Scanning Speed ◽  
Hierarchical Architecture ◽  
Electrochemical Window ◽  
A Current

As one of the most outstanding high-efficiency and environmentally friendly energy storage devices, the supercapacitor has received extensive attention across the world. As a member of transition metal oxides widely used in electrode materials, manganese dioxide (MnO2) has a huge development potential due to its excellent theoretical capacitance value and large electrochemical window. In this paper, MnO2 was prepared at different temperatures by a liquid phase precipitation method, and polyaniline/manganese dioxide (PANI/MnO2) composite materials were further prepared in a MnO2 suspension. MnO2 and PANI/MnO2 synthesized at a temperature of 40 °C exhibit the best electrochemical performance. The specific capacitance of the sample MnO2-40 is 254.9 F/g at a scanning speed of 5 mV/s and the specific capacitance is 241.6 F/g at a current density of 1 A/g. The specific capacitance value of the sample PANI/MnO2-40 is 323.7 F/g at a scanning speed of 5 mV/s, and the specific capacitance is 291.7 F/g at a current density of 1 A/g, and both of them are higher than the specific capacitance value of MnO2. This is because the δ-MnO2 synthesized at 40 °C has a layered structure, which has a large specific surface area and can accommodate enough electrolyte ions to participate the electrochemical reaction, thus providing sufficient specific capacitance.

XXXVIII.—Observations with a Current Meter in Loch Ness

1909 ◽  
Vol 29 ◽  
pp. 619-647 ◽  
Author(s):  
E. M. Wedderburn ◽  
W. Watson
Keyword(s):  
Experimental Investigation ◽  
Fixed Point ◽  
Great Lakes ◽  
Large Lake ◽  
Deep Lakes ◽  
Small Lake ◽  
Stormy Weather ◽  
Set Up ◽  
A Current ◽  
Made In

One of the authors having made an experimental investigation on the currents produced in a trough of water by a blast of air driven along the surface of the water, it was desired to test the correctness of his deductions by actual observations in a large lake. Loch Ness was chosen on account of its length and uniformity of basin, as it was thought that the length and narrowness of the loch would lead to clearly defined currents being set up in the lake. The sequel showed, as in the case of observations on seiches, that it would have been better to confine attention to a smaller lake, for a twofold reason, (1) because in a large lake the difficulties of observations are much greater than in a small lake during stormy weather, and in very deep lakes the difficulties in the way of obtaining a fixed point from which to use the current meter are formidable, and (2) because it would seem from a few observations made in Loch Garry (Ness Basin) that currents are more defined and more regular in small than in great lakes.

scholarly journals Binder free 2D aligned efficient MnO2 micro flowers as stable electrodes for symmetric supercapacitor applications

RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 36886-36894 ◽  
Author(s):  
Anil A. Kashale ◽  
Madagonda M. Vadiyar ◽  
Sanjay S. Kolekar ◽  
Bhaskar R. Sathe ◽  
Jia-Yaw Chang ◽  
...  
Keyword(s):  
Thin Film ◽  
Stainless Steel ◽  
Specific Capacitance ◽  
Stainless Steel Mesh ◽  
Steel Mesh ◽  
Symmetric Supercapacitor ◽  
Binder Free ◽  
Thin Film Electrodes ◽  
Supercapacitor Applications

δ-MnO2 thin film electrodes (M1) deposited on stainless steel mesh using CBD were used in symmetric supercapacitor device (SSM/M1//M1/SSM) with aqueous 1 M Na2SO4 electrolyte. The device shows 138% retention of specific capacitance after 2500 cycles.

Electrospun Polyacrylonitrile-Keratin Derived Carbon Nanofiber as Electrode for Asymmetric Supercapacitor

2021 ◽  
Vol 878 ◽  
pp. 56-61
Author(s):  
Joel L. Villanueva ◽  
Gabriel Angelo Tapas ◽  
Jezza B. Bayot ◽  
Menandro C. Marquez ◽  
Ruth R. Aquino
Keyword(s):  
Carbon Nanofiber ◽  
Fiber Diameter ◽  
Average Distance ◽  
Protein Solution ◽  
Nanosized Materials ◽  
Triangular Shape ◽  
Double Layer Capacitor ◽  
Polymeric Solutions ◽  
And Diffusion ◽  
A Current

Electrospinning is one method to produce nanosized materials in a form of fibers with a large variety of polymeric solutions. In this research, Polyacrylonitrile (PAN) dissolved in N,N-Dimethylformamide (DMF) as the primary solvent, loaded with keratin protein solution, was blended using the said fabrication method to change its properties. The loading of the keratin solution concentrates varied from 5%, 7%, and 10% relative to the volume of the solution. The PAN-keratinnano substances were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Cyclic Voltammetry (CV), and Galvanostatic Cycling with Potential Limitation (GCPL) to illustrate the properties of the fiber. The SEM micrographs showed that upon adding keratin into the PAN the diameter lengths of the imaged fibers were still nanofiber. As the viscosity of the solution is increased, the beads become bigger, the average distance between beads and the fiber diameter increases, and the shape of the beadings changes from spherical to spindle-like. In addition, CV and GCPL revealed that as the potential scan rate is being increased, the surrounded area of the CV also increases. The presence of redox peaks implies that a faradaic process occurs. The migration and diffusion of ions can be supported by the carbonized fibers. GCPL shows the triangular shape with symmetric charging and discharging slopes at a current density of 0.5mah, 1mah, 1.5mah and 2.5mah, confirming that the electrodes behave as a pure electric double layer capacitor (EDLC).

Electrochemical Characterisation of Poly(aniline-co-N-methylaniline) and Poly(aniline-co-N-ethylaniline) Films on Pencil Graphite Electrode for Supercapacitor Applications

2013 ◽  
Vol 66 (7) ◽  
pp. 825 ◽  
Author(s):  
Andac Arslan ◽  
Evrim Hur
Keyword(s):  
Specific Capacitance ◽  
Low Voltage ◽  
Electrochemical Impedance ◽  
Graphite Electrode ◽  
Pencil Graphite Electrode ◽  
Supercapacitor Electrode ◽  
Copolymer Films ◽  
Electrochemical Storage ◽  
Supercapacitor Applications ◽  
Poly Aniline

In this work, poly(aniline-co-N-methylaniline) (co-PNMA) and poly(aniline-co-N-ethylaniline) (co-PNEA) have been electrochemically synthesised on pencil graphite electrode (PGE) surface to use as an electrode material for supercapacitors. The films have been formed from aqueous solution of monomers and sulfuric acid as electrolyte. The copolymer films have been characterised by cyclic voltammetry (CV), Mott-Schottky (MS) analysis, and scanning electron microscopy (SEM). The electrochemical storage properties of uncoated electrode and copolymer coated electrodes (PGE/co-PNMA and PGE/co-PNEA) have been investigated via CV, electrochemical impedance spectroscopy (EIS), and repeating chronopotentiometry (RCP) methods in 0.100 M H2SO4 solution. Experimental results indicate that PGE/co-PNMA exhibits higher specific capacitance than PGE/co-PNEA. Highest specific capacitance values of the PGE/co-PNMA and PGE/co-PNEA have been obtained as 213.85 mF g–1 (17.7 mF cm–2) and 48.60 mF g–1 (4.36 mF cm–2) at 50 mV s–1, respectively when compared with that of uncoated PGE which is 1.63 mF g–1 (0.14 mF cm–2). Charge-discharge characteristics of the electrodes have shown that both of the electrodes can be used as supercapacitor electrode active materials for low voltage (<10 V) applications.

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