Other

Jeol Ltd.

Advanced Capacitor Technologies, Inc.

Nippon Oil Corporation

Nippon Petroleum Refining Company, Limited

Akinori Mogami

Michio Okamura

Makoto Takeuchi

Katsumi Koike

Minoru Noguchi

Manabu Iwaida

Eisuke Komazawa

Masaaki Yamagishi

Takamichi Maruyama

Hiroshi Kobayashi

Takashi Oyama

Tamotsu Tano

Yukinori Kude

Motohiro Naitoh

The present invention provides a novel carbon material for a electric double-layer capacitor having characteristics entirely different from prior art activated carbon. The capacitor develops a capacitance by a mechanism entirely different from the mechanism of an electric double-layer capacitor using activated carbon. The novel capacitor has improved performance including capacitance. The capacitor has polarized electrodes immersed in an organic electrolyte. The electrodes are made of a nonporous carbon having crystallites of graphite-like carbon. When a voltage is applied, electrolyte ions are intercalated between the layers of the crystallites of the graphite-like carbon together with the solvent. Thus, electric double layers are formed. Intercalation is induced by the first cycle of charging. In the second and following cycles, the capacitance is developed.

Carbon material and method of making same

Present invention relates to an electric double-layer capacitor having positive and negative electrodes containing nonporous carbon as an electrode active material. In the nonporous carbon, multiple layers of graphene having an average interplanar spacing dof 0.350 to 0.380 nm have been grown well. The positive and negative electrodes are impregnated with an electrolyte solution. The nonporous carbon is obtained by activating easily graphitizable carbon, which in turn is obtained by calcining needle coke or pitch made infusible. The elctrolyte solution is either a liquid electrolyte having a planar molecular structure or an electrolyte solution consisting of a liquid electrolyte dissolved in an organic solvent.

Electric double-layer capacitor

A raw material composite 10 for a carbon material used in an electric double layer capacitor contains microcrystalline carbon having a layered crystal structure similar to graphite, and is formed a carbon material for an electric double layer capacitor by undergoing an activation treatment. Here, the raw material composite is characterized in that a Hardgrove grindability index HGI defined by ASTMD-409-71 is 50 or above, an interlayer distance dof the microcrystalline carbon determined by an X-ray diffraction method is 0.343 NM or below, and a crystallite size Lcof the microcrystalline carbon determined by the X-ray diffraction method is 3.0 nm or below.

Raw material composite for carbon material used in electric double layer capacitor, manufacturing method of the same, electric double layer capacitor, and manufacturing method of the same

The present invention provides a novel electric double-layer capacitor made of a carbon material having characteristics entirely different from those of the prior art activated carbon. The capacitor develops a capacitance by a mechanism entirely different from the mechanism of an electric double-layer capacitor using activated carbon. The novel capacitor has improved performance including capacitance. The capacitor has polarized electrodes immersed in an organic electrolyte. The electrodes are made of a nonporous carbon having crystallites of graphite-like carbon. When a voltage is applied, electrolyte ions are intercalated between the layers of the crystallites of the graphite-like carbon together with the solvent. Thus, electric double layers are formed. Intercalation is induced by the first cycle of charging. In the second and following cycles, the capacitance is developed.

Electric double-layer capacitor and carbon material therefor

There is disclosed an electric double-layer capacitor that is adapted for use in an electric vehicle, for example, and uses aluminum collector electrodes. A native oxide film is formed on each aluminum electrode. Hard granular carbon is made to penetrate through the oxide film into each aluminum electrode. The aluminum electrodes are connected with positive and negative polarizing electrodes, respectively, via the granular carbon, thus lowering the contact resistance.

Method of fabricating double-layer capacitor with lower contact resistance

An electrical storage capacitor system that efficiently initializes itself to its initial state during pause intervals between charging/discharging cycles of operation without providing any special initializing cycles. The capacitor system comprises capacitors connected in series to store electricity, a variation decision means for judging the amount of variation in amount of charge between the capacitors, an operation decision means for judging whether the capacitors are being charged or discharged, and a initializing charging means for charging the capacitors to initialize themselves to their initial state according to the results of decisions made by the variation decision means and by the operation decision means.

Electrical storage capacitor system having initializing function

There is disclosed a power supply system comprising capacitors that are connected switchably via a small number of switches to decrease variations of an output voltage. The switches comprise a series connection switch and first and second sets of switches. A control means controls the first set of switches, the second set of switches, and the series connection switch to switch connection of the capacitors of the first and second sets among a first state in which the first set of capacitors is connected in series with the second set of capacitors, a second state in which the first set of capacitors is connected in parallel with the second set of capacitors, and a third state in which one or more capacitors of the first set are connected in parallel with one or more capacitors of the second set.

Capacitor power supply with switches to decrease variations in output voltage

There is disclosed a capacitor module capable of having an improved packing density and, hence, an improved energy storage density. A capacitor bank using such capacitor modules is also disclosed. Furthermore, an electrical energy storehouse using such capacitor banks is disclosed. Supercapacitor cells connected in series are housed in a box-like capacitor module. A heat dissipator is mounted on an end surface of the module. Parallel monitors connected in parallel with the capacitor cells, respectively, are mounted to the heat dissipator. Such capacitor modules are stacked to form a capacitor bank. The heat-dissipating surface of each module is located on the outside of the bank and exposed. The modules are held in the bank so that they can be taken out of the bank individually. Capacitor banks making a pair are located back-to-back such that their heat-dissipating surface face outward. Pairs of capacitor banks arranged in this way are arranged vertically and horizontally via passages and via space permitting the modules to be taken out.

Capacitor module, bank of such modules, and storehouse housing such banks

An electric double-layer capacitor that is adapted for use in an electric vehicle, for example, and uses aluminum collector electrodes. A native oxide film is formed on each aluminum electrode. Hard granular carbon is made to penetrate through the oxide film into each aluminum electrode. The aluminum electrodes are connected with positive and negative polarizing electrodes, respectively, via the granular carbon, thus lowering the contact resistance.

Electric double-layer capacitor having hard granular carbon material penetrating into the aluminum collector electrodes

There is disclosed an electrical storage system comprising capacitors that are prevented from deteriorating at elevated temperatures. The electrical storage system is adapted for use in a hybrid electric vehicle or electric vehicle. The storage system comprises a bank of capacitors, a charger for charging the capacitor bank, a temperature switch connected across the capacitor bank and a discharge resistor connected in series with the temperature switch. The temperature switch is closed at a limit temperature (e.g., 70.degree. C.) at which deterioration of the capacitors can be neglected in a fully charged condition. When the temperature of the capacitor bank reaches the limit value, the temperature switch is closed. The capacitor bank is discharged via both the temperature switch and the discharge resistor. This suppresses deterioration of the capacitors at elevated temperatures.

Electrical storage system made of capacitors

There is disclosed a direct imaging type SIMS (secondary ion mass spectrometry) instrument having a mass analyzer comprising superimposed fields. The superimposed fields consist of a toroidal electric field and a uniform magnetic field substantially perpendicular to the electric field. In an imaging mode, and ion image of the region of a sample which is irradiated with a primary beam is focused onto a two-dimensional ion detector by the mass analyzer having the superimposed fields. In TOF (time-of-flight) mass spectrometric mode, the intensity of the magnetic field of the superimposed fields is reduced down to zero to use only the electric field. Pulsed secondary ions from the surface of the sample are passed through the electric field and are separated according to mass with the lapse of time on the principle of TOF mass spectrometry.

Growing community of inventors

Tokyo, Japan

Akinori Mogami