Abstract: To produce activated carbon for an electrode of an electric double-layer capacitor, the following steps are carried out sequentially: a step of subjecting a massive mesophase pitch to a pulverizing treatment to provide a pulverized powder; a step of subjecting the pulverized powder to an infusibilizing treatment under conditions of a temperature in a range of 300° C. (inclusive) to 450° C. (inclusive) in the atmospheric air current, a step of subjecting the pulverized powder to a carbonizing treatment under conditions of a temperature in a range of 600° C. (inclusive) to 900° C. (inclusive) in an inert gas current to provide a carbonized powder, a step of subjecting the carbonized powder to an alkali activating treatment under conditions of a temperature in a range of 500° C. (inclusive) to 1,000° C. (inclusive) in an inert gas atmosphere, followed by the post treatments, thereby producing alkali-activated carbon, and a step of subjecting the alkali-activated carbon to a pulverizing treatment.

Abstract: To produce activated carbon for an electrode of an electric double-layer capacitor, the following steps are carried out sequentially: a step of subjecting a massive mesophase pitch to a pulverizing treatment to provide a pulverized powder; a step of subjecting the pulverized powder to an infusibilizing treatment under conditions of a temperature in a range of 300° C. (inclusive) to 450° C. (inclusive) in the atmospheric air current, a step of subjecting the pulverized powder to a carbonizing treatment under conditions of a temperature in a range of 600° C. (inclusive) to 900° C. (inclusive) in an inert gas current to provide a carbonized powder, a step of subjecting the carbonized powder to an alkali activating treatment under conditions of a temperature in a range of 500° C. (inclusive) to 1,000° C. (inclusive) in an inert gas atmosphere, followed by the post treatments, thereby producing alkali-activated carbon, and a step of subjecting the alkali-activated carbon to a pulverizing treatment.

Abstract: The present invention provides a method for easily determining the specifications of a fuel cell and a capacitor constituting a fuel cell power generation system according to an operational mode of an electric load connected to the fuel cell power generation system and a fuel cell power generation system having its specification set using the method. The specifications of the fuel cell and the capacitor connected in parallel to the fuel cell are determined by meeting three requirements: the driving performance, the fuel economy, and the durability, in good balance.

Abstract: In an electric double-layer capacitor, a solution of a quaternary ammonium borofluoride compound in propylene carbonate is used as an electrolyte. The electrode includes alkali-activated carbon made using meso-phase pitch as a starting material, and a conductive filler having a rest potential smaller than that of the alkali-activated carbon in the electrolyte. The amount Fc of conductive filler incorporated in the electrode is set in a range of 10% by weight?Fc?40% by weight. Such electric double-layer capacitor has a large electrostatic capacity and excellent durability.

Abstract: A polarizing electrode for an electric double layer capacitor has good moldability and can achieving higher density of electrode and higher capacity, and an electric double layer capacitor employs the same. The electric double layer capacitor is made of an activated carbon obtained by activating a hard-to-graphitize material (for example, phenol resin) with water vapor, and the activated carbon has a median particle size within a range from 4 ?m to 8 ?m in the particle size distribution and at least a peak observed on the side of smaller particle size than the median particle size in the particle size distribution.

Abstract: A method for easily determining the specifications of a fuel cell and a capacitor constituting a fuel cell power generation system according to an operational mode of an electric load connected to the fuel cell power generation system. The specifications of the fuel cell and the capacitor connected in parallel to the fuel cell are determined by a first step for determining a limit value di/dt_lmt of an increasing rate di/dt of an output current density per unit cell area of the fuel cell according to at least an operational mode of the electric load connected to the fuel cell system, a second step for determining an internal resistance Rfc of the fuel cell on the basis of a current-voltage (I-V) characteristic of the fuel cell based on the di/dt_lmt determined by the first step, and a third step for determining the internal resistance Rcap of the capacitor such that a characteristic value K calculated by weighted multiplication of Rfc determined by the second step and Rcap lies within the range of 0.

Abstract: In an electric double-layer capacitor, a solution of a quaternary ammonium borofluoride compound in propylene carbonate is used as an electrolyte. The electrode includes alkali-activated carbon made using meso-phase pitch as a starting material, and a conductive filler having a rest potential smaller than that of the alkali-activated carbon in the electrolyte. The amount Fc of conductive filler incorporated in the electrode is set in a range of 10% by weight?Fc?40% by weight. Such electric double-layer capacitor has a large electrostatic capacity and excellent durability.

Abstract: In an electric double-layer capacitor, a solution of a quaternary ammonium borofluoride compound in propylene carbonate is used as an electrolyte. The electrode includes alkali-activated carbon made using meso-phase pitch as a starting material, and a conductive filler having a rest potential smaller than that of the alkali-activated carbon in the electrolyte. The amount Fc of conductive filler incorporated in the electrode is set in a range of 10% by weight≦Fc≦40% by weight. Such electric double-layer capacitor has a large electrostatic capacity and excellent durability.

Abstract: A polarizing electrode for an electric double layer capacitor has good moldability and can achieving higher density of electrode and higher capacity, and an electric double layer capacitor employs the same. The electric double layer capacitor is made of an activated carbon obtained by activating a hard-to-graphitize material (for example, phenol resin) with water vapor, and the activated carbon has a median particle size within a range from 4 &mgr;m to 8 &mgr;m in the particle size distribution and at least a peak observed on the side of smaller particle size than the median particle size in the particle size distribution.

Abstract: A cylindrical electric double-layer capacitor includes a cylindrical sealed vessel housing an electrode roll and an electrolyte solution. The electrode roll is formed of a rolled superposed assembly having band-shaped positive and negative poles and two band-shaped separators sandwiching one of the band-shaped positive and negative poles. Each of the band-shaped positive and negative poles includes a band-shaped collector and a pair of polarizing electrodes formed in a laminated manner on opposite surfaces of the band-shaped collector. In a state in which the electrode roll has been accommodated in the sealed vessel along with the electrolyte solution, an outer diameter D1 of the electrode roll and an inner diameter D2 of the sealed vessel are brought into a relationship of D1=D2 by at least one of swelling of the polarizing electrodes caused by the electrolyte solution and expansion of the polarizing electrodes caused by an electrical charge.

Abstract: A cylindrical electric double-layer capacitor includes a cylindrical sealed vessel housing an electrode roll and an electrolyte solution. The electrode roll is formed of a rolled superposed assembly comprising band-shaped positive and negative poles and two band-shaped separators sandwiching one of the band-shaped positive and negative poles. Each of the band-shaped positive and negative poles includes a band-shaped collector and a pair of polarizing electrodes formed in a laminated manner on opposite surfaces of the band-shaped collector. In a state in which the electrode roll has been accommodated in the sealed vessel along with the electrolyte solution, an outer diameter D1 of the electrode roll and an inner diameter D2 of the sealed vessel are brought into a relationship of D1=D2 by at least one of swelling of the polarizing electrodes caused by the electrolyte solution and expansion of the polarizing electrodes caused by an electrical charge.

Abstract: An activated carbon for electric double layer capacitor whose rate of FS (filling swing) in an &agr;s-plot by the nitrogen adsorption method is at most 27 cm3/g STP. An activated carbon electrode formed with the activated carbon. An electric double layer capacitor equipped with the activated carbon electrodes as polarizable electrodes and having excellent durability.

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%.

Abstract: An amorphous solid solution of V.sub.2 O.sub.5, CoO.sub.2, P.sub.2 O.sub.5, MO (wherein M represents an alkaline earth metal element) and at least one lithium compound selected from the group consisting of lithium-oxygen compounds, lithium halides and lithium oxygen acid salts is formed by melting precursor materials therefore, then the melt is put into water or pressed with metal plates to quench it, and the solid solution is heat treated above its glass transition temperature, the resulting solid solution being used as a cathode material for a lithium battery, thereby obtaining the lithium battery preventing the capacity of a carbon anode from lowering and excellent in long-term cycle stability.

Abstract: An alkali ion-absorbing/desorbing carbon material excellent in absorption and desorption of alkali ions and useful for an electrode material for a secondary battery or an anode material of a lithium battery is obtained by heat treatment at 300.degree. to 1000.degree. C. of an organic polymer having an aromatic structure, wherein the monomers of the aromatic organic polymer are linked together by o-bonding or m-bonding, or wherein the aromatic organic polymer has a branched structure or a crosslinked structure. The carbon material has a randomly stacked, condensed aromatic ring structure.

Abstract: An organic polymer compound such as poly(p-phenylene) is heat treated under an atmosphere of an inert gas such as argon at 500.degree. to 1,500.degree. C., preferably in the vicinity of a carbonization temperature (the range from the carbonization temperature to the carbonization temperature+300.degree. C.) to obtain a carbon material having properties of both a carbon substance and an organic substance.

Abstract: A cathode material for a lithium battery comprising an amorphous solid solution comprising V.sub.2 O.sub.5, CoO.sub.2, P.sub.2 O.sub.5 and MO, wherein M represents an alkaline earth metal element and CoO.sub.2 is contained in an amount of 0 to 10 mol % based on V.sub.2 O.sub.5, which is produced by melting a mixture of V.sub.2 O.sub.5, CoO.sub.2, P.sub.2 O.sub.5 and MO to form a melt, wherein CoO.sub.2 is contained in an amount of 0 to 10 mol % based on V.sub.2 O.sub.5, and then putting the melt into water or pressing the melt with metal plates to pulverize it.