Patents by Inventor Akihiko Koiwai

Akihiko Koiwai 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).

  • Patent number: 7026058
    Abstract: A multilayered hydrogen absorbing body is provided which is formed by laminating at least two types of hydrogen absorbing materials. The degrees of strains cause due to absorption/desorption of hydrogen are different between the hydrogen absorbing materials adjacent to each other.
    Type: Grant
    Filed: July 22, 2003
    Date of Patent: April 11, 2006
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Shin-ichi Towata, Masakazu Aoki, Tatsumi Hioki, Akio Itoh, Akihiko Koiwai, Toshihiro Mouri, Katsushi Saito
  • Publication number: 20040110023
    Abstract: A multilayered hydrogen absorbing body is provided which is formed by laminating at least two types of hydrogen absorbing materials. The degrees of strains cause due to absorption/desorption of hydrogen are different between the hydrogen absorbing materials adjacent to each other.
    Type: Application
    Filed: July 22, 2003
    Publication date: June 10, 2004
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventors: Shin-Ichi Towata, Masakazu Aoki, Tatsumi Hioki, Akio Itoh, Akihiko Koiwai, Toshihiro Mouri, Katsushi Saito
  • Patent number: 6620553
    Abstract: A lithium secondary battery exhibiting very high safety, which is ensured by restraining both the generation of flammable gas caused by the decomposition of an electrolyte, and the emission of oxygen from a positive active material even during overcharging. The lithium secondary battery includes a positive electrode of which an active material is a lithium transition metal composite oxide, a negative electrode of which an active material is a carbon material, and a nonaqueous electrolyte containing an organic solvent in which a lithium salt is dissolved. The nonaqueous electrolyte contains at least one kind of conductive polymer-forming monomers which have an alkyl group and is electrochemically polymerizable on the positive electrode within a battery operation voltage, and at least one kind of film-forming agents which electrochemically decompose within the battery operation voltage to form films on a surface of the negative electrode.
    Type: Grant
    Filed: July 10, 2001
    Date of Patent: September 16, 2003
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Tohru Shiga, Akihiko Koiwai, Shigehiro Kawauchi
  • Publication number: 20020018926
    Abstract: A lithium secondary battery exhibiting very high safety, which is ensured by restraining both the generation of flammable gas caused by the decomposition of an electrolyte, and the emission of oxygen from a positive active material even during overcharging. The lithium secondary battery includes a positive electrode of which an active material is a lithium transition metal composite oxide, a negative electrode of which an active material is a carbon material, and a nonaqueous electrolyte containing an organic solvent in which a lithium salt is dissolved. The nonaqueous electrolyte contains at least one kind of conductive polymer-forming monomers which have an alkyl group and is electrochemically polymerizable on the positive electrode within a battery operation voltage, and at least one kind of film-forming agents which electrochemically decompose within the battery operation voltage to form films on a surface of the negative electrode.
    Type: Application
    Filed: July 10, 2001
    Publication date: February 14, 2002
    Applicant: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO
    Inventors: Tohru Shiga, Akihiko Koiwai, Shigehiro Kawauchi
  • Patent number: 6077628
    Abstract: A nonaqueous electrolytic solution for a battery, which contains a supporting electrolyte which reacts with water to produce an acid; and a complex-forming compound which forms an inert complex by reacting with water and a supporting electrolyte to prevent acid generation.
    Type: Grant
    Filed: April 20, 1998
    Date of Patent: June 20, 2000
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Kensuke Takechi, Akihiko Koiwai, Tohru Shiga
  • Patent number: 5958622
    Abstract: A negative electrode material capable of absorbing and desorbing lithium is comprised of a mixture of coke and graphite. The amount of graphite in the mixture is near to that which induces percolation transition. Preferably, the amount of graphite in the mixture is 2 to 37 wt % relative to the total amount of the coke and graphite. The coke may be prepared by heating raw coke from oil or coal at 500 to 900.degree. C. The coke may be 0.06 or more in the atomic ratio of hydrogen to carbon and 0.003 or more in the atomic ratio of oxygen to carbon. The graphite may be 0.5 .mu.m to 30 .mu.m in a mean particle size. Lithium secondary batteries comprising the negative electrodes have a large discharge capacity.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: September 28, 1999
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Yoshitsugu Kojima, Akihiko Koiwai, Nobuaki Suzuki, Satoru Yamamoto