Patents by Inventor Keisuke Ohara

Keisuke Ohara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20180309118
    Abstract: Negative electrode active material particles for a lithium ion secondary battery include base material particles and a coating. The coating covers a surface of the base material particles. The base material particles contain a first carbon material. The coating contains lithium titanate and a second carbon material. When a ratio of an intensity of a D band to an intensity of a G band in a laser Raman spectrum is set as an R value, the second carbon material has a larger R value than the first carbon material.
    Type: Application
    Filed: April 23, 2018
    Publication date: October 25, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhisa Takeda, Keisuke Ohara
  • Patent number: 10056617
    Abstract: A secondary battery includes a wound electrode assembly in which a positive electrode sheet, a negative electrode sheet and a separator are stacked and wound. The positive electrode sheet is provided with a long positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is disposed on the positive electrode current collector. The negative electrode sheet is provided with a long negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is disposed on the negative electrode current collector. The separator is interposed between the positive electrode sheet and the negative electrode sheet. The negative electrode current collector has a first active material layer-free region at one edge of the negative electrode current collector in a winding direction of an axis of the wound electrode assembly.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: August 21, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tatsuya Hashimoto, Keisuke Ohara, Yuji Yokoyama, Yusuke Fukumoto
  • Patent number: 10026941
    Abstract: A separator 1 for a nonaqueous electrolyte secondary battery, includes a resin-made substrate (2) and a porous heat resistance layer (4) disposed on the substrate. The porous heat resistance layer includes an inorganic filler (6) and hollow bodies (7). The hollow body includes a shell portion and a hollow portion. The shell portion is formed of an acryl resin. The hollow portion is formed inside the shell portion. An opening portion extending through the shell portion to spatially interconnect the hollow portion and the outside of the shell portion is formed in the shell portion.
    Type: Grant
    Filed: November 26, 2014
    Date of Patent: July 17, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hiroya Umeyama, Tatsuya Hashimoto, Yusuke Fukumoto, Keisuke Ohara, Kouichi Toriyama
  • Patent number: 10020511
    Abstract: This invention provides a lithium secondary battery that comprises a positive electrode comprising a positive electrode active material layer and a negative electrode comprising a negative electrode active material layer. The positive electrode active material layer and the negative electrode active material layer are placed to face each other. The negative electrode active material layer has an area A comprising a non-positive-electrode-facing portion that does not face the positive electrode active material layer. The area A comprises a negative electrode active material, a hot-melt binder and a temperature-sensitive thickener. The hot-melt binder has a melting point and the temperature-sensitive thickener has a gelation temperature both in a range of 45° C. to 100° C.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: July 10, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tatsuya Hashimoto, Keisuke Ohara, Yuji Yokoyama, Yusuke Fukumoto
  • Publication number: 20180108903
    Abstract: Provided is a method for producing a negative electrode by using a negative electrode active material and ceramic particles, the method ensuring satisfactory coatability of the paste and high peel strength and hardness of the obtained negative electrode active material layer. The method for producing a negative electrode disclosed herein includes a step of coating a negative electrode paste including a negative electrode active material and ceramic particles on a negative electrode current collector; a step of drying the coated negative electrode paste to form a negative electrode active material layer; and a step of pressing the negative electrode active material layer. The ceramic particles have an aspect ratio of 1.5 or more and 20 or less. The ceramic particles have a short side length of 1/5 or less of an average particle diameter of the negative electrode active material.
    Type: Application
    Filed: October 12, 2017
    Publication date: April 19, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhisa TAKEDA, Yuji YOKOYAMA, Keisuke OHARA
  • Publication number: 20180076462
    Abstract: A lithium ion secondary battery includes a negative electrode, a positive electrode, and a non-aqueous electrolyte solution. The non-aqueous electrolyte solution includes a lithium salt and an aprotic solvent. The negative electrode includes a composite particle. The composite particle includes a negative electrode active material and tungsten trioxide. The negative electrode active material contains graphite. The tungsten trioxide is disposed on a surface of the negative electrode active material.
    Type: Application
    Filed: July 31, 2017
    Publication date: March 15, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhisa TAKEDA, Keisuke OHARA
  • Patent number: 9806336
    Abstract: Provided is a positive electrode for nonaqueous electrolyte secondary batteries including a positive electrode mixture layer formed of a positive electrode mixture paste containing a positive electrode active material. The positive electrode active material has a particle diameter of 2 ?m or more and less than 7 ?m. The positive electrode mixture layer includes a first mixture layer in which a maximum diameter of pores formed between particles of the positive electrode active material is more than 1.0 ?m and 5.0 ?m or less, and a second mixture layer in which a maximum diameter of the pores is 1.0 ?m or less. The second mixture layer is arranged closer to the current collector than the first mixture layer. A ratio of a thickness of the first mixture layer to a thickness of the second mixture layer is more than 0.1 and 1.0 or less.
    Type: Grant
    Filed: September 21, 2012
    Date of Patent: October 31, 2017
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tatsuya Hashimoto, Yusuke Fukumoto, Keisuke Ohara, Yuji Yokoyama
  • Publication number: 20170170464
    Abstract: A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, a separator provided between the positive electrode and the negative electrode, and a nonaqueous electrolytic solution at least held by the separator. The positive electrode has a positive electrode collector and a positive electrode mixture layer provided on the positive electrode collector. The positive electrode mixture layer has a first powder and a second powder. The first powder includes a first positive electrode active material, a first conductive material, and an organic-based binder. The second powder includes a second positive electrode active material, a second conductive material, and a water-based binder.
    Type: Application
    Filed: May 29, 2015
    Publication date: June 15, 2017
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hiroya UMEYAMA, Tatsuya HASHIMOTO, Keisuke OHARA, Yusuke FUKUMOTO, Yuji YOKOYAMA
  • Patent number: 9647261
    Abstract: The present invention provides a non-aqueous electrolyte secondary battery that comprises a positive electrode sheet comprising a positive electrode active material layer, and a negative electrode sheet comprising a negative electrode active material layer. The positive electrode sheet and the negative electrode sheet are arranged such that the positive electrode active material layer and the negative electrode active material layer face each other. The negative electrode active material layer comprises a face-to-face region NF that faces the positive electrode active material layer and a non-face-to-face region NNF that does not face the positive electrode active material layer. The non-face-to-face region NNF includes a high density part NHD having a density higher than that of the region face-to-face NF.
    Type: Grant
    Filed: November 12, 2012
    Date of Patent: May 9, 2017
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Keisuke Ohara, Tatsuya Hashimoto, Yuji Yokoyama, Yusuke Fukumoto
  • Publication number: 20170047569
    Abstract: A nonaqueous electrolyte secondary battery (100) includes a positive electrode (30), a negative electrode (40), a separator (50), a nonaqueous electrolytic solution, and a battery case (10). The positive electrode includes a positive electrode current collector (32) and a positive electrode active material layer (34). The separator includes a separator substrate (52) and a heat resistance layer (54). The separator substrate has an opposite surface opposite the positive electrode active material layer. The heat resistance layer constitutes at least a part of the opposite surface and contains a heat-resistant filler and a binder. The positive electrode active material layer has an adjacent region (X). The heat resistance layer has an opposite region (Y) opposite at least an end portion of the adjacent region. The end portion of the adjacent region is adjacent to a positive electrode current collector exposure portion (33). The opposite region contains at least a calcium salt of carboxymethyl cellulose.
    Type: Application
    Filed: April 15, 2015
    Publication date: February 16, 2017
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hideyuki SAKA, Tatsuya HASHIMOTO, Yusuke FUKUMOTO, Keisuke OHARA, Kouichi TORIYAMA
  • Patent number: 9559383
    Abstract: The present invention provides a sealed lithium secondary battery in which redox shuttle reactions of an aromatic compound that is an overcharge inhibitor are inhibited, and the aromatic compound decomposes appropriately, and a desired amount of gas can be generated more stably than in conventional instances, even in high-temperature environments. In the sealed lithium secondary battery (100), an electrode assembly (80) and an electrolyte are accommodated in a battery case (50) that is provided with a current interrupt device (30). The electrolyte comprises a compound that is capable of suppressing drops in viscosity of the electrolyte as a result of a rise in temperature in a temperature region up to 100° C., and an aromatic compound capable of generating hydrogen gas when a predetermined battery voltage is exceeded.
    Type: Grant
    Filed: January 17, 2012
    Date of Patent: January 31, 2017
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Masahiro Morita, Toshihiko Mitsuhashi, Keisuke Ohara, Yuji Yokoyama, Yusuke Fukumoto, Tatsuya Hashimoto
  • Publication number: 20160380250
    Abstract: A separator 1 for a nonaqueous electrolyte secondary battery, includes a resin-made substrate (2) and a porous heat resistance layer (4) disposed on the substrate. The porous heat resistance layer includes an inorganic filler (6) and hollow bodies (7). The hollow body includes a shell portion and a hollow portion. The shell portion is formed of an acryl resin. The hollow portion is formed inside the shell portion. An opening portion extending through the shell portion to spatially interconnect the hollow portion and the outside of the shell portion is formed in the shell portion.
    Type: Application
    Filed: November 26, 2014
    Publication date: December 29, 2016
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hiroya UMEYAMA, Tatsuya HASHIMOTO, Yusuke FUKUMOTO, Keisuke OHARA, Kouichi TORIYAMA
  • Publication number: 20160181619
    Abstract: A secondary battery includes a wound electrode assembly in which a positive electrode sheet, a negative electrode sheet and a separator are stacked and wound. The positive electrode sheet is provided with a long positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is disposed on the positive electrode current collector. The negative electrode sheet is provided with a long negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is disposed on the negative electrode current collector. The separator is interposed between the positive electrode sheet and the negative electrode sheet. The negative electrode current collector has a first active material layer-free region at one edge of the negative electrode current collector in a winding direction of an axis of the wound electrode assembly.
    Type: Application
    Filed: July 30, 2014
    Publication date: June 23, 2016
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tatsuya HASHIMOTO, Keisuke OHARA, Yuji YOKOYAMA, Yusuke FUKUMOTO
  • Publication number: 20150280209
    Abstract: The present invention provides a non-aqueous electrolyte secondary battery that comprises a positive electrode sheet comprising a positive electrode active material layer, and a negative electrode sheet comprising a negative electrode active material layer. The positive electrode sheet and the negative electrode sheet are arranged such that the positive electrode active material layer and the negative electrode active material layer face each other. The negative electrode active material layer comprises a face-to-face region NF that faces the positive electrode active material layer and a non-face-to-face region NNF that does not face the positive electrode active material layer. The non-face-to-face region NNF includes a high density part NHD having a density higher than that of the region face-to-face NF.
    Type: Application
    Filed: November 12, 2012
    Publication date: October 1, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Keisuke Ohara, Tatsuya Hashimoto, Yuji Yokoyama, Yusuke Fukumoto
  • Publication number: 20150255786
    Abstract: Provided is a positive electrode for nonaqueous electrolyte secondary batteries including a positive electrode mixture layer formed of a positive electrode mixture paste containing a positive electrode active material. The positive electrode active material has a particle diameter of 2 ?m or more and less than 7 ?m. The positive electrode mixture layer includes a first mixture layer in which a maximum diameter of pores formed between particles of the positive electrode active material is more than 1.0 ?m and 5.0 ?m or less, and a second mixture layer in which a maximum diameter of the pores is 1.0 ?m or less. The second mixture layer is arranged closer to the current collector than the first mixture layer. A ratio of a thickness of the first mixture layer to a thickness of the second mixture layer is more than 0.1 and 1.0 or less.
    Type: Application
    Filed: September 21, 2012
    Publication date: September 10, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tatsuya HASHIMOTO, Yusuke FUKUMOTO, Keisuke OHARA, Yuji YOKOYAMA
  • Publication number: 20150221951
    Abstract: This invention provides a lithium secondary battery that comprises a positive electrode comprising a positive electrode active material layer and a negative electrode comprising a negative electrode active material layer. The positive electrode active material layer and the negative electrode active material layer are placed to face each other. The negative electrode active material layer has an area A comprising a non-positive-electrode-facing portion that does not face the positive electrode active material layer. The area A comprises a negative electrode active material, a hot-melt binder and a temperature-sensitive thickener. The hot-melt binder has a melting point and the temperature-sensitive thickener has a gelation temperature both in a range of 45° C. to 100° C.
    Type: Application
    Filed: September 10, 2012
    Publication date: August 6, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tatsuya Hashimoto, Keisuke Ohara, Yuji Yokoyama, Yusuke Fukumoto
  • Patent number: 8986882
    Abstract: The present invention relates to a current collector including a base portion with a flat face, primary projections projecting from the flat face, and secondary projections projecting from the top of the primary projections. The present invention also relates to a current collector including a base portion with a flat face and primary projections projecting from the flat face, wherein the roughening rate of the top of the primary projections is 3 to 20. By using such a current collector, separation of the active material from the current collector can be inhibited when using an active material that has a high capacity but undergoes a large expansion at the time of lithium ion absorption.
    Type: Grant
    Filed: December 26, 2007
    Date of Patent: March 24, 2015
    Assignee: Panasonic Intellectual Property Management Co., Ltd.
    Inventors: Shuji Ito, Yasutaka Kogetsu, Kazuya Iwamoto, Kazuyoshi Honda, Taisuke Yamamoto, Yasuhiro Ueyama, Keisuke Ohara, Hitoshi Katayama
  • Publication number: 20140342200
    Abstract: The present invention provides a sealed lithium secondary battery in which redox shuttle reactions of an aromatic compound that is an overcharge inhibitor are inhibited, and the aromatic compound decomposes appropriately, and a desired amount of gas can be generated more stably than in conventional instances, even in high-temperature environments. In the sealed lithium secondary battery (100), an electrode assembly (80) and an electrolyte are accommodated in a battery case (50) that is provided with a current interrupt device (30). The electrolyte comprises a compound that is capable of suppressing drops in viscosity of the electrolyte as a result of a rise in temperature in a temperature region up to 100° C., and an aromatic compound capable of generating hydrogen gas when a predetermined battery voltage is exceeded.
    Type: Application
    Filed: January 17, 2012
    Publication date: November 20, 2014
    Inventors: Masahiro Morita, Toshihiko Mitsuhashi, Keisuke Ohara, Yuji Yokoyama, Yusuke Fukumoto, Tatsuya Hashimoto
  • Patent number: 8399129
    Abstract: A negative electrode for a lithium secondary battery of the present invention includes a current collector and a negative electrode active material layer carried on the current collector. The negative electrode active material layer includes a plurality of columnar particles. The current collector has a surface including a depression and a plurality of projected regions defined by the depression. The projected regions carry the columnar particles. Further, the present invention relates to a lithium secondary battery using the foregoing negative electrode. According to the present invention, it is possible to provide a high-capacity negative electrode excellent mainly in cycle characteristics for a lithium secondary battery, and a lithium secondary battery including the same.
    Type: Grant
    Filed: October 2, 2007
    Date of Patent: March 19, 2013
    Assignee: Panasonic Corporation
    Inventors: Masaya Ugaji, Masaki Hasegawa, Taisuke Yamamoto, Keisuke Ohara, Yasutaka Kogetsu, Takuhiro Nishimura
  • Patent number: 8273479
    Abstract: A negative electrode for a lithium secondary battery according to the present invention includes a current collector 12, and an active material layer 14 formed on the current collector 12. The active material layer 14 includes a plurality of negative-electrode active material members 16 disposed on the current collector 12. Each negative-electrode active material member 16 is oxide, including a first region 18 of a relatively high oxygen concentration and a plurality of second regions 20 having an oxygen concentration which is lower than that of the first region 18. The first region 18 extends from a bottom face of each negative-electrode active material member 16 in a direction away from the surface of the current collector. The plurality of second regions 20 are alternately disposed on both sides of the first region 18.
    Type: Grant
    Filed: April 11, 2008
    Date of Patent: September 25, 2012
    Assignee: Panasonic Corporation
    Inventors: Masaki Hasegawa, Masaya Ugaji, Keisuke Ohara, Hitoshi Matsumoto