Abstract: Activated carbon for an electrode of an electric double-layer capacitor is produced by subjecting a carbon material sequentially to a carbonizing treatment and an alkali activating treatment, and by using a carbon material. The carbon material used is a condensed polycyclic aromatic compound (CPAC) which has a condensed ring (CR) and at least one aliphatic hydrocarbon radical (R) bonded to said condensed ring (CR). The condensed ring (CR) includes at least one alicyclic hydrocarbon structure moiety (ALC). In an analysis chart resulting from a 13C-NMR spectroscopy of the condensed polycyclic aromatic compound, a signal intensity ratio IL/IR is equal to or larger than 0.2, and a signal intensity ratio IC/IR is equal to or larger than 0.14, wherein IR represents a signal intensity of an aromatic peak; IL represents a signal intensity of an aliphatic hydrocarbon peak; and IC represents a signal intensity of an alicyclic hydrocarbon peak.

Abstract: A method for preparing the electrolytic solution of an electric double-layer capacitor is provided, which undergoes cyclical charging and discharging within a predetermined operating range of voltage. The capacitor includes the electrolytic solution, electrodes and a casing for housing the electrolytic solution and electrodes. The method includes the step of preparing an ion concentration of the electrolytic solution so that the electrolytic solution turns to a nonconductor at a first predetermined voltage, which is so set as to be equal to or greater than the upper limit of the predetermined operating range of voltage and less than or equal to the maximum allowable voltage of the capacitor.

Abstract: Activated carbon for an electrode of an electric double-layer capacitor is produced by subjecting a carbon material sequentially to a carbonizing treatment and an alkali activating treatment, and by using a carbon material. The carbon material used is a condensed polycyclic aromatic compound (CPAC) which has a condensed ring (CR) and at least one aliphatic hydrocarbon radical (R) bonded to said condensed ring (CR). The condensed ring (CR) includes at least one alicyclic hydrocarbon structure moiety (ALC). In an analysis chart resulting from a 13C-NMR spectroscopy of the condensed polycyclic aromatic compound, a signal intensity ratio IL/IR is equal to or larger than 0.2, and a signal intensity ratio IC/IR is equal to or larger than 0.14, wherein IR represents a signal intensity of an aromatic peak; IL represents a signal intensity of an aliphatic hydrocarbon peak; and IC represents a signal intensity of an alicyclic hydrocarbon peak.

Abstract: A carbonized product 10 used for production of activated carbon for an electrode of an electric double-layer capacitor, includes a plurality of crystallites 12 each having a graphite structure in an amorphous carbon matrix 11. The interlayer distance d002 of the crystallites 12 is set a value equal to or larger than 0.347 nm. Thus, by using this carbonized product, it is possible to produce activated carbon having a high electrostatic capacity density (F/cc) for an electrode of an electric double-layer capacitor.

Abstract: A cylindrical electric double-layer capacitor 1 includes an electrode roll made by spirally rolling a superposed assembly formed of a band-shaped positive pole and a band-shaped negative pole superposed on each other with a first separator interposed therebetween and a second separator superposed on one of the band-shaped positive and negative poles so that the second separator is located on an outermost side, and a vessel in which the electrode roll is accommodated. A cylindrical electrode is mounted on the electrode roll to come into contact with an outer peripheral surface of the electrode roll. The polarity of the cylindrical electrode is set to be opposite from that of a portion of one of the band-shaped positive and negative poles which is located on an outermost periphery of the electrode roll.

Abstract: A cylindrical electric double-layer capacitor 1 includes an electrode roll made by spirally rolling a superposed assembly formed of a band-shaped positive pole and a band-shaped negative pole superposed on each other with a first separator interposed therebetween and a second separator superposed on one of the band-shaped positive and negative poles so that the second separator is located on an outermost side, and a vessel in which the electrode roll is accommodated. A cylindrical electrode is mounted on the electrode roll to come into contact with an outer peripheral surface of the electrode roll. The polarity of the cylindrical electrode is set to be opposite from that of a portion of one of the band-shaped positive and negative poles which is located on an outermost periphery of the electrode roll.

Abstract: A cylindrical electric double-layer capacitor includes an electrode winding which is formed by superposing band-shaped positive and negative electrodes one on another with a first separator interposed therebetween, superposing a second separator onto one of the band-shaped positive and negative electrodes to provide a superposed material, and by spirally winding the superposed material such that the second separator is located on an outermost side, and a container having the electrode winding accommodated therein. A cylindrical electrode is provided on an inner peripheral surface of the container opposed to an outer peripheral surface of the electrode winding. The polarity of the cylindrical electrode is set at a polarity opposite from the polarity of that portion of the band-shaped negative electrode, which is located on an outermost periphery of the electrode winding.

Abstract: An electrochemical capacitor is provided having double-layer electrode elements interposed with a separator. The electrode elements being made of activated carbon and impregnated with a nonaqueous electrolytic liquid yields a capacitor with low internal resistance, greater capacitance and higher energy density. Methods for producing the activated carbon electrodes and the capacitor assembly are also described.

Abstract: An activated carbon for an electrode of an electric double-layer capacitor includes a plurality of crystallites having a graphite structure in an amorphous carbon, in which the interlaminar distance d002 of the plurality of crystallites is in a range of 0.388≦d002≦0.420 nm.

Abstract: An activated carbon for an electrode of an electric double-layer capacitor includes an activated carbon fiber produced by using a graphitizing carbon, and an activated carbon powder obtained by pulverizing the activated carbon fiber, thereby increasing the density of the electrode.

Abstract: Activated carbon for electric double-layer capacitor has a high electrostatic capacity density. An area rate of edge faces in a surface (including inner surfaces of fine bores) of the activated carbon for an electric double-layer capacitor is equal to or higher than 20%.

Abstract: Activated carbon for use in an electric double layer capacitor is in the form of particles produced by crushing activated carbon or fibers of activated carbon. The particles have a surface covered at least partly with a laminated structure layer of graphite formed along the surface.

Abstract: Disclosed herein is a process for producing active carbon suitable for use in electrodes for an organic solvent type electric double layer capacitor, comprising calcining an easily graphitizable organic substance and then subjecting the resultant carbonized product to an alkali activation treatment, wherein the alkali activation treatment comprises a first alkali activation treatment at a temperature within a first range and a second alkali activation treatment at a temperature within a second range, said temperature within the second range being higher than that of the first activation treatment, and one of both alkali activation treatments is performed after the other alkali activation treatment.

Abstract: An active carbon suitable for use in electrodes for an organic solvent type electric double layer capacitor, which is obtained by calcining an easily graphitizable organic substance and then activating the resultant carbonized product with an alkali, wherein a mode in the pore size distribution of the active carbon according to a transmission electron microscope (TEM) image analysis method falls within a range of 10-20 angstroms, and an conjunctive pore rate, which is expressed by a proportion of the total area of pores having an area not smaller than 500 square angstroms to the whole pore area in the TEM image, is at least 20%.