Showing papers on "Supercapacitor published in 2004"
TL;DR: Batteries, fuel cells and supercapacitors belong to the same family of energy conversion devices and are needed to service the wide energy requirements of various devices and systems.
Abstract: Electrochemical energy conversion devices are pervasive in our daily lives. Batteries, fuel cells and supercapacitors belong to the same family of energy conversion devices. They are all based on the fundamentals of electrochemical thermodynamics and kinetics. All three are needed to service the wide energy requirements of various devices and systems. Neither batteries, fuel cells nor electrochemical capacitors, by themselves, can serve all applications.
6,230 citations
TL;DR: In this article, the authors proposed a family of energy conversion devices based on the fundamentals of electrochemical thermodynamics and kinetics, including batteries, fuel cells, and supercapacitors.
Abstract: Electrochemical energy conversion devices are pervasive in our daily lives. Batteries, fuel cells and supercapacitors belong to the same family of energy conversion devices. They are all based on the fundamentals of electrochemical thermodynamics and kinetics. All three are needed to service the wide energy requirements of various devices and systems. Neither batteries, fuel cells nor electrochemical capacitors, by themselves, can serve all applications.
561 citations
TL;DR: In this article, the electrochemical properties of composites prepared from an electrically conducting polymer poly(3,4-ethylenedioxythiophene), i.e., PEDOT and multiwalled carbon nanotubes (CNTs), have been investigated for supercapacitor application.
464 citations
TL;DR: In this article, four square centimeter carbon-carbon supercapacitor cells were assembled with Al current collectors in organic electrolyte, and different treatments of the current collectors were made in order to increase the super-capacitors performances.
396 citations
TL;DR: In this paper, the authors compared the performance of a battery-type rechargeable electrode with a double-layer capacitor-type electrode and showed the advantages and disadvantages of using a third electrode as a reference.
311 citations
TL;DR: In this article, the use of ionic liquids based on 1-buthyl-3-methyl-imidazolium as electrolytes in an activated carbon/poly(3methylthiophene) hybrid supercapacitor was investigated.
274 citations
TL;DR: Anhydrous mesoporous ruthenium oxide was synthesized by a simple non-ionic surfactant templating method using Pluronic 123 and tested as an active electrode material for an electrochemical supercapacitor as mentioned in this paper.
237 citations
TL;DR: In this paper, integrated carbon nanotube (CNT) electrodes for electric double layer capacitor (EDLC) were fabricated and the coin-type EDLC cells with directly grown CNT electrodes exhibited a rectangular cyclic voltammogram even at a scan rate of 1000 mV/s.
221 citations
TL;DR: In this article, the performance of two-electrode supercapacitors built with electrodes prepared from the templated carbon was tested in acidic, alkaline and organic electrolyte solutions, and high values of capacitance were obtained with a rectangular shape of the voltammograms over a wide range of scan rates indicating a quick charge propagation.
221 citations
TL;DR: In this paper, two types of supercapacitors, redox and hybrid, based on poly(ethylenedioxythiophene) (PEDOT) and MSP-20 powder as electrode materials with Et 4 NBF 4 in PC and LiPF 6 in EC/DMC as electrolyte solutions.
204 citations
TL;DR: In this article, a symmetric supercapacitors based on these nanocomposites were fabricated by using gel polymer PVA-H3PO4-H2O as electrolyte, and a maximum specific capacitance of 1263 F/g was obtained for the RuO2 which was loading on TiO2 nanotubes.
TL;DR: In this paper, a carbon material with a highly ordered porous structure was successfully prepared by a templating procedure using an organized mesoporous silica (type MCM-48) as template and various carbon precursors (propylene, sucrose or pitch).
Abstract: Interesting carbon materials with a highly ordered porous structure, including micro- and mesopores, were successfully prepared by a templating procedure using an organized mesoporous silica (type MCM-48) as template and various carbon precursors (propylene, sucrose or pitch). The carbon material is obtained by introducing the carbon precursor by means of two different routes (liquid or gas) into the porous structure of the silica matrix. After the removal of silica by acid treatment, a carbon material with an organized porosity and porous characteristics defined mainly by the nature of the carbon precursor is recovered. The as-synthesized carbon exhibits an interesting electrochemical double-layer capacitance behavior due to its original and particular nanostructure and especially its regular interconnected nanoporosity. The performance of the supercapacitors was investigated in acidic, alkaline and organic electrolytic solutions. High values of capacitance in aqueous and organic media were obtained. The cyclic voltammograms display a rectangular shape over a wide range of scan rates indicating a quick charge propagation. The possibility to synthesize well-tailored nanostructured carbon materials is of prime importance to further forecast the optimal porous characteristics of an electrode material used for capacitor applications.
TL;DR: In this article, the specific capacitance and charge-discharge periods of thin-film ruthenium oxide electrodes are found to be dependent on the electrode thickness, which is explained by considering the morphological changes that take place with increasing film thickness.
TL;DR: In this article, polybenzimidazol (PBI) solutions of dimethyl acetamide (DMAc) were electrospun to be webs consisting of 250-nm ultra-fine fibers.
TL;DR: In this paper, a multiwalled carbon nanotube array was fabricated by chemical vapor deposition (CVD) in the template of porous alumina from the carbonaceous source of C 2 H 2 in the presence of a catalyst of ferric metals.
TL;DR: In this article, a 40 Wh/kg Li-ion battery using a Li4Ti5O12 nanostructured anode and a composite activated carbon LiCoO2 cathode was built using plastic Li-ION processing based on PVDF-HFP binder and soft laminate packaging.
TL;DR: In this paper, the pseudocapacitive properties of thin sputtered manganese oxide films with thickness ranging from 20 to 200nm have been investigated using cyclic voltammetry at a rate of 5mV/s.
TL;DR: In this paper, multi-layer and co-deposition composite electrodes were prepared by introducing the carbon powders into the anodically deposited hydrous manganese oxide, and the surface morphology and crystal structure of the electrodes were examined by scanning electron microscope and glancing angle X-ray diffraction.
TL;DR: In this paper, the status of commercial aqueous and nonaqueous battery systems is reviewed, and applications of various battery systems are reviewed, as well as the current state of the art.
Abstract: Battery systems have undergone significant improvements over the past 25 years. Older systems have been updated with new materials and constructions. New lithium and nickel systems have been introduced, especially in the rechargeable segment, and have undergone tremendous growth and reached maturity. The technology and applications of the various battery systems are reviewed here, and the status of commercial aqueous and nonaqueous systems updated. NEC first introduced electrochemical capacitors in August 1978 under the trade name Supercapacitor. Electrochemical capacitor technology has evolved from first generation products with low energy density for memory protection applications through several generations of designs to create megajoule-size capacitors for transportation and power quality applications.
TL;DR: In this article, a poly(methyl)thiophene was used as a cathode in a laminated plastic asymmetric hybrid electrochemical device with a nano-structured Li4Ti5O12 anode.
TL;DR: In this article, carbon fibers from viscose fibers activated with KOH were analyzed by thermogravimetric and differential thermal analysis in order to get information on the temperature dependence of the KOH reaction with carbon.
TL;DR: In this article, PACS: 82.45.Gj; 81.40.Gh; 78.30.Kt; 68.43.Yz; 82.47.Uv; 82,45.Fk; 85.35.
Abstract: 7 pages.-- PACS: 82.47.Uv; 82.45.Fk; 85.35.Kt; 68.43.Mn; 82.45.Yz; 82.45.Gj; 81.40.Gh; 78.30.Na
TL;DR: In this paper, the capacitive characteristics of activated carbon fabrics (ACFs) coated on the graphite substrates were systematically investigated by means of cyclic voltammetry and the galvanostatic charge discharge technique.
TL;DR: In this article, the double layer capacitance of nanorods synthesized via hydrothermal method was studied in aqueous 0.1 M KOH and NaCl solutions and the nanomaterial was immobilized on paraffin impregnated graphite electrode by abrasive transfer technique.
TL;DR: In this article, an electrochemical supercapacitor in all solid configuration using perfluorosulfonate ionomer as polymer electrolyte has been successfully realized, and the capacitance performance of these devices is comparable or better than traditional systems, which use sulfuric acid as electrolyte.
TL;DR: In this article, a variant of ac impedance spectroscopy is applied to monitor and control electrochemical cells and appliances without need for reference values and knowledge of control points in advance, and the problem of determining electrolyte concentrations unambiguously from electrolyte resistance, although the conductivity of the solution has a maximum and changes nonlinearly with the concentration.
TL;DR: In this article, a modified sol-gel method with annealing in air for supercapacitors was demonstrated in which the specific capacitance of activated carbon (denoted as AC) measured at 5mV/cm2 was significantly increased from 26.8 to 38.7% by the adsorption of RuOx nanoparticles with ultrasonic weltering in 1M NaOH for 30 min.
TL;DR: In this article, a sandwich-type supercapacitor consisting of two similar activated carbon fabric-polyaniline composite electrodes was demonstrated to exhibit excellent performance (i.e., highly reversibility and good stability) in NaNO3.
TL;DR: In this paper, the effects of Nafion loading in electrodes on the performance of supercapacitors have been investigated by electrochemical impedance spectroscopy, and the results showed that the capacitors with lower nafion content had higher conductivities and better capacitance performances.
Abstract: The effects of Nafion loading in electrodes on the performance of supercapacitors have been investigated in this work. Electrodes based on carbon material were prepared with Nafion loading varying from 10 to 50 wt %, and the optimal loading was investigated by electrochemical impedance spectroscopy. The capacitors with lower Nafion content had higher conductivities and better capacitance performances. A maximum specific capacitance of 110 F/g (carbon of the electrode) was achieved for the capacitor with 10% Nafion loading in the electrode. Impedance spectroscopy was also used to evaluate separately the resistance of the Nafion electrolyte and of the carbon/Nafion layer of the electrodes. The results showed that the electrode with 50% Nafion gives a resistance about 50% higher with respect to that with 10% Nafion, even if the specific capacitance of the supercapacitor using the former electrode is only 20% lower. The similar performance exhibited by these all-solid supercapacitors compared to those of conventional devices, based on liquid electrolytes, is likely due to the high conductivity of Nafion and the contribution of the bound water surrounding the Nafion electrolyte in the electrode. A life cycling test carried out on a supercapacitor for 20,000 cycles, in cyclic voltammetry mode, showed variations of <3% of capacitance.