Patents Assigned to Advanced Capacitor Technologies, Inc.
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Patent number: 8785048Abstract: A carbonaceous material used as a polarizable active material in an electric double layer capacitor is characterized in that, when measured by an electron spin resonance method without adding any additives, the obtained peak line width is 2 mT or less, and the peak intensity, which is converted into a number of unpaired electrons per 1 g, is 1×1019 or more. A method for producing the carbonaceous material includes removing residual functional groups from the carbonaceous material so that reactions between the residual functional groups and the electrolytic liquid are suppressed when forming a capacitor.Type: GrantFiled: June 13, 2006Date of Patent: July 22, 2014Assignees: Cataler Corporation, Advanced Capacitor Technologies, Inc.Inventors: Yasuyuki Higaonna, Tetsuya Kume, Yasunari Iwata, Makoto Takeuchi
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Publication number: 20090104105Abstract: To provide a carbonaceous material for electric double layer capacitor, carbonaceous material which demonstrates a good charge/discharge characteristic, when it makes an electric double layer capacitor. A carbonaceous material according to the present invention for electric double layer capacitor is used as a polarizable active material in electric double layer capacitor, and is characterized in that, when measuring it by an electron spin resonance method without adding any additive thereto, the obtained peak line width is 2 mT or less, and in that the peak intensity, which is converted into a number of unpaired electron per 1 g, is 1×1019 or more.Type: ApplicationFiled: June 13, 2006Publication date: April 23, 2009Applicants: CATALER CORPORATION, ADVANCED CAPACITOR TECHNOLOGIES, INCInventors: Yasuyuki Higaonna, Tetsuya Kume, Yasunari Iwata, Makoto Takeuchi
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Patent number: 7273597Abstract: 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.Type: GrantFiled: October 28, 2003Date of Patent: September 25, 2007Assignee: Advanced Capacitor Technologies, Inc.Inventors: Makoto Takeuchi, Katsumi Koike, Akinori Mogami, Takamichi Maruyama
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Patent number: 7180725Abstract: 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 d002 of 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.Type: GrantFiled: March 3, 2004Date of Patent: February 20, 2007Assignee: Advanced Capacitor Technologies, Inc.Inventors: Makoto Takeuchi, Akinori Mogami, Katsumi Koike
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Patent number: 7141230Abstract: A method of efficiently removing active oxy-hydrogens (e.g., existing as hetero element-containing functional groups such as COOH, CHO, and OH) present in a carbon material at a relative low temperature. The invention also provides a carbon-activating material adapted for use in a polarizable electrode typically used in an electrical double-layer capacitor. The method of removing residual active oxy-hydrogens in the carbon material starts with mixing the carbon material and a transition metal or a transition metal compound. The resulting mixture is thermally processed within a stream of a reducing gas. Preferably, the transition metal or transition metal compound is removed from the thermally processed mixture.Type: GrantFiled: June 6, 2002Date of Patent: November 28, 2006Assignee: Advanced Capacitor Technologies, Inc.Inventor: Makoto Takeuchi
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Publication number: 20060057052Abstract: A method of efficiently removing active oxy-hydrogens (e.g., existing as hetero element-containing functional groups such as COOH, CHO, and OH) present in a carbon material at a relative low temperature. The invention also provides a carbon-activating material adapted for use in a polarizable electrode typically used in an electrical double-layer capacitor. The method of removing residual active oxy-hydrogens in the carbon material starts with mixing the carbon material and a transition metal or a transition metal compound. The resulting mixture is thermally processed within a stream of a reducing gas. Preferably, the transition metal or transition metal compound is removed from the thermally processed mixture.Type: ApplicationFiled: November 3, 2005Publication date: March 16, 2006Applicant: Advanced Capacitor Technologies, Inc.Inventor: Makoto Takeuchi
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Patent number: 6885170Abstract: A connection-switched capacitor storage system comprises plural capacitors, parallel monitors connected with the capacitors, respectively, switches for switching the connections of the capacitors from a series combination to a parallel combination or vice versa, and a control portion. The parallel monitors bypass the charging current for the capacitors when the terminal voltages of the capacitors exceed a given voltage, thus limiting increases of the terminal voltages of initializing the terminal voltages of the capacitors to their original level. The control portion controls initialization and switching of the connections of the capacitors. The control portion causes the parallel monitors to initialize the capacitors near the voltage at which the connections of the capacitors are switched by the switches.Type: GrantFiled: October 2, 2002Date of Patent: April 26, 2005Assignees: Advanced Capacitor Technologies, Inc., Okamura Laboratory, Inc., Kabushiki Kaisha PowersystemsInventors: Michio Okamura, Masaaki Yamagishi