Showing papers on "Supercapacitor published in 1995"
TL;DR: In this article, the performance of a polymer redox supercapacitor based on poly(dithieno[3,4-b: 3′,4′-d] thiophene) in liquid and in polymer gel electrolyte was tested for capacity, energy density, power density and self-discharge.
60 citations
TL;DR: In this paper, a carbon-based double-layer supercapacitor using a proton conducting electrolyte (Nylon 6-10, 2H3PO4) has been developed and its performances are compared to those of the same device using an aqueous electrolyte.
41 citations
10 Jan 1995
TL;DR: In this article, the authors describe efforts at development of commercially viable bipolar lead acid batteries capable of sub-second discharges at specific powers of 50-300 kW/kg, including design and performance.
Abstract: It is possible to design batteries which have specific powers comparable to capacitors for sub-second pulses (50-200 kW/kg), but which retain the specific energy superior to capacitors (30-100 J/kg). In 1990 LaFollette and Bennion described the design and performance of small (0.2 cm/sup 2/) bipolar lead acid batteries which, for 0.1-1 ms, were discharged at specific power levels of up to several hundred kW/kg. Improvements to the electrode designs were later made. Full size bipolar batteries were built which demonstrated that the results obtained for the laboratory-scale batteries of LaFollette and Bennion could be successfully scaled up. The purpose of this paper is to describe efforts at development of commercially viable bipolar lead acid batteries capable of sub-second discharges at specific powers of 50-300 kW/kg, including design and performance. >
31 citations
TL;DR: In this article, a number of promising material technologies have been identified for use in electrochemical capacitors, including activated carbon fibers, foams, and composites, doped conducting polymers, and mixed metal oxides.
Abstract: Electrochemical capacitors (ultracapacitors) are one approach to meeting the high power requirements for the energy storage system in an electric vehicle. Energy is stored in an electrochemical capacitor by charge separation in the double layer formed in the micropores of a very high surface area electrode material, which does not undergo chemical change as in a battery. Consequently, the material requirements for capacitors are very different from those of batteries. In the last several years, a number of promising material technologies have been identified for use in electrochemical capacitors. These include activated carbon fibers, foams, and composites, doped conducting polymers, and mixed metal oxides. The most important material property is its specific capacitance (F/gm or F/cm3). Carbon materials with specific capacitances of 100 to 300 F/gm have been developed. Doped polymer materials having specific capacitances of 300 to 400 F/gm are also being studied. In addition to high specific capacitance, the electrode material must also have a low electronic resistivity ( < 0.1 Ω-cm) in order that charge can be distributed with minimum voltage drop in the electrode. Electrochemical capacitor cells have been fabricated using the various material technologies with both aqueous and organic electrolytes. Tests of the cells have shown near ideal charge/discharge characteristics — that is, the voltage versus time curves are nearly linear for constant current tests. The energy densities of 1 V cells, using aqueous electrolytes, are 1 to 1.5 W-h/kg and those of 3 V cells, using organic electrolytes are 7 to 10 W-h/kg. Most of the cells have high power densities of 1 to 3 kW/kg. Numerous new materials for electrochemical capacitors have been identified, processed, and tested in electrodes and cells in recent years and progress is rapid in this relatively new field of research.
29 citations
TL;DR: In this article, a lithium-ion rechargeable battery based on carbon anode, a viable replacement for lithium metal anode has been developed, which showed good stability during cycling, and is expected to be a suitable anode material in lithium ion rechargeable batteries.
22 citations
10 Jan 1995
TL;DR: In this paper, the performance of chemical double layer capacitors (DLC) with aqueous and nonaqueous electrolytes have made it possible to seriously consider them for commercialization.
Abstract: Recent advances in the performance of chemical double layer capacitors (DLC) with aqueous and nonaqueous electrolytes have made it possible to seriously consider them for commercialization. Nonaqueous (organic) carbon based laboratory monopolar devices have recently met key US Department of Energy (DOE) mid-term specifications (>5 W h/kg, >500 W/kg and >100000 life cycles) for load-leveling electric vehicles batteries. All DLC technologies currently under development by DOE are discussed. Each technology has distinct advantages and none are clear winners at this time. A study has been completed by the General Electric Company on the interface electronics needed to best utilize the energy of capacitors while load-leveling batteries. System costs are presented based on this study, several battery technologies, and capacitor projections. >
22 citations
TL;DR: In this article, a classification and a characteristics of industrially produced Japanese small electric double layer capacitors are reviewed, and the structure and performance of power capacitors under development as well as materials and performance for small EDLCs are discussed.
Abstract: An electric double layer capacitor (EDLC) based on the charge storage at the interface between a high surface area carbon electrode and an electrolyte solution is widely used as maintenance-free power source for IC memories and microcomputers. New applications for electric double-layer capacitors have been proposed in recent years. The popularity of these devices is derived from their high energy density relative to conventional capacitors and their long cycle life and high power density relative to batteries. In this paper a classification and a characteristics of industrially produced Japanese small EDLCs are reviewed. Structure and performance of power capacitors under development as well as materials and performance of industrially produced small capacitors are discussed.
14 citations
TL;DR: In this article, a method for producing thin film solid polymer electrolytes and more particularly to produce solid thin reinforced terpolymer electrolyte films for use in the fabrication of solid state rechargeable batteries and other solid state electrochemical devices such as supercapacitors, fuel cells, sensors and the like.
12 citations
TL;DR: In this article, a coin-type lithium-ion rechargeable batteries made of crystalline V2O5 for the cathode and pitch-based carbon for the anode was developed.
11 citations
Journal Article•
TL;DR: In this article, the authors proposed a system that combines high specific energy (i.e., energy per unit of weight or volume), high specific power, high efficiency, long life, and reasonable cost.
Abstract: New high-power capacitors could give future electric and hybrid vehicles the boost they need for adequate acceleration. Electric and hybrid vehicles of the future will need some additional muscle to give drivers the quick acceleration they demand from their cars. In fact, developing energy/power storage technology for electric drivetrains is a big part of the challenge in commercializing low-emission vehicles. What`s needed is a system that combines high specific energy (i.e., energy per unit of weight or volume), high specific power, high efficiency, long life, and reasonable cost. One contender for this role is the electrochemical capacitor, or ultracapacitor. Also known as supercapacitors, these electrochemical devices are designed for the rapid storage and release of large quantities of energy. It may be that high-power ultracapacitors can provide future electric cars with the muscle that even advanced storage batteries may not be able to give.
9 citations
Patent•
24 Mar 1995
TL;DR: In this paper, an energy storage unit is charged by solar cells via charging electronics if the light is insufficient, the unit can be charged conventionally, regardless of whether the cells are fully discharged The solar cells are arranged within the computer casing, or form an integral part of it.
Abstract: The device has an energy source unit without a memory effect, eg nickel-metal hydride cells, chargeable alkali-manganese batteries, or lithium ion batteries or Goldcap (RTM) , Supercap (RTM) capacitors The energy storage unit is charged by solar cells via charging electronics If the light is insufficient, the unit can be charged conventionally, regardless of whether the cells are fully discharged The solar cells are arranged within the computer casing, or form an integral part of it
TL;DR: In this article, the following topics are discussed: new batteries for old airplanes; new charge controls for lengthening battery life; fast methods for batteries charging; AC conductance measurement based battery testing; pulse power; bipolar lead-acid batteries vs supercapacitors; Ni electrode cells for spacecraft; worn-out battery disposal; recycling technology; vehicle batteries cost; high energy content batteries; and energy storage for electric utilities.
Abstract: The following topics are discussed: new batteries for old airplanes; new charge controls for lengthening battery life; fast methods for batteries charging; AC conductance measurement based battery testing; pulse power; bipolar lead-acid batteries vs supercapacitors; Ni electrode cells for spacecraft; worn-out battery disposal; recycling technology; vehicle batteries cost; high energy content batteries; and energy storage for electric utilities. >