Ngk Insulators, Inc.

Other

Kabushiki Kaisha Toshiba

International Superconductivity Technology Center

Yusuke Niiori

Hiroyuki Katsukawa

Hitoshi Yoshida

Ryusuke Ushikoshi

Koichi Umemoto

Atsushi Sakon

Makoto Takeuchi

Kazuhiro Nobori

Michio Okamura

Izumi Hirabayashi

Yasuji Yamada

Masahiro Murasato

Junichi Kawashima

Tamaki Masegi

An electrochemical capacitor is provided, including an organic electrolyte solution and polarized electrodes immersed in the organic electrolyte solution. As an active substance of the polarized electrodes, the reaction product of an electrochemical reaction of a partially oxidized carbon material that contains fine crystals of graphite-like carbon in an organic electrolyte solution is used. The electrochemical capacitor has a high electrostatic capacity density based on a pseudo-capacity.

Electrochemical capacitor

Disclosed is an electric double layer capacitor including polarizable electrodes immersed in an organic electrolyte, wherein a carbon material for forming the polarizable electrode is a carbon material including graphite-like microcrystalline carbon produced by effecting a heat treatment together with at least one of an alkali metal and an alkali metal compound at not less than a temperature at which alkali metal vapor is generated, and an electrostatic capacity is expressed by insertion of ions of a solute of the organic electrolyte into a space between microcrystalline carbon layers of the carbon material. Accordingly, it is possible to achieve an electrostatic capacity and a withstand voltage which exceed those of the conventional electric double layer capacitor based on the activated carbon system.

Electric double layer capacitor and method for producing the same

An electrochemical capacitor wherein electrode members include polarizing electrodes, whose main ingredient is a carbon material having partially oxidized graphite-like microcrystalline carbon, separators, and collectors is immersed in a organic electrolytic solution, the polarizing electrodes expanding on charging and contracting on discharging. Ions with ionic radii of 0.33 nm or less are used as the electrolyte cations of the organic electrolytic solution. The cell container holding electrode members and the electrolytic solution is provided with stress relaxing structure. Either collectors or separators are elastomers. The separators are sponge-like porous insulator with continuous pores.

Electrochemical capacitors

A process for producing an electrochemical capacitor including an organic electrolytic solution and electrode bodies immersed in the organic electrolytic solution, each comprising a polarizing electrode (composed mainly of a carbon material containing a partially oxidized, graphite-like microcrystalline carbon), a separator and a collector, in which capacitor each polarizing electrode gives rise to volume expansion when charged and volume contraction when discharged, is provided. The process includes: a step of placing each electrode body and the organic electrolytic solution in a cell container to form a unit cell, a step of placing the unit cell or a cell integrate obtained by electrically connecting a plurality of such unit cells, in a first capacitor container to constitute a first electrochemical capacitor, a step of subjecting the first electrochemical capacitor to charging-discharging cycles until the maximum value of the stress caused by the volume expansion of each polarizing electrode during charging becomes almost constant, and a step of transferring, after the maximum value of the stress has become almost constant, the unit cell or the cell integrate into a second capacitor container to constitute a second electrochemical capacitor. The process can provide an electrochemical capacitor which causes no plastic deformation of the capacitor container and which is superior in durability and reliability.

Method for producing electrochemical capacitor

An oxide superconductor comprises a base material consisting of a single crystalline oxide, an oxide superconductor film consisting of a Y123 compound and formed on the single crystalline oxide base material, and a coating film consisting essentially of a Ba--Cu--O oxide and covering the surface of the oxide superconductor film, the coating film having a thermal expansion coefficient higher than that of the oxide superconductor film.

Oxide superconductor and method of manufacturing the same

A ceramic heater includes a substrate made of aluminum nitride, a resistive heating element buried in the substrate and made of a metal having a high melting point, and terminals electrically connected to the resistive heating element and buried in said substrate. The terminals are made of a metal having a high melting point and a coefficient of thermal expansion not smaller than that of the substrate. The metal of the resistive heating element has a coefficient of thermal expansion not smaller than that of the substrate. The coefficient of thermal expansion of each of the terminals and the resistive heating element is in a range from 5.0.times.10.sup.-6 /.degree.C. to 8.3.times.10.sup.-6 /.degree.C.

Ceramic heaters and heating devices using such ceramic heaters

A ceramic heater composed of a ceramic substrate and a resistant heating element embedded within the ceramic substrate along a predetermined planar pattern is obtained by holding a convolution of a spiral-coiled high melting metallic filament in the above predetermined planar pattern and heat-treating the convolution at a temperature not higher than a primary recrystallization commencement temperature of the high melting metal under a non-oxidative atmosphere to provide the resistant heating element, embedding the resulting resistant heating element within a ceramic shaped body, and then, sintering the ceramic shaped body. In a preferred embodiment, the resistant heating element is a convolution of a spiral coil, the number of coils per a unit length of said convolution is set at a predetermined value in each of defined domains of the ceramic heater, and when the number of coils per a unit length of the convolution is determined, the relation of the maximal value, the minimal value and the mean value, of all the determined numbers of coils in the above domains, satisfies the formula:

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Inuyama, Japan

Yusuke Niiori