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).

  • Patent number: 8187755
    Abstract: Having a current collector having a concave portion and a convex portion at least on one side, and a columnar body formed on the convex portion of the current collector, the columnar body contains an active material for inserting and extracting lithium ions bonding at least with oxygen, and the oxygen content ratio of the active material of the columnar body becomes smaller as going away from the interface of the current collector.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: May 29, 2012
    Assignee: Panasonic Corporation
    Inventors: Masaya Ugaji, Keisuke Ohara, Kazuhiro Watanabe
  • Patent number: 8029933
    Abstract: A negative electrode for a non-aqueous electrolyte secondary battery reversibly inserting and extracting lithium ions, and including current collector having concave portion and convex portion on at least one surface thereof; and columnar body formed on convex portion of current collector and including columnar body portions laminated in n stages (n?2) in which a content ratio of an element sequentially changes in the longitudinal direction of the current collector. The content ratio of an element is different between in an odd stage and in an even stage of columnar body portions.
    Type: Grant
    Filed: September 21, 2007
    Date of Patent: October 4, 2011
    Assignee: Panasonic Corporation
    Inventors: Masaya Ugaji, Masaki Hasegawa, Taisuke Yamamoto, Keisuke Ohara
  • Patent number: 7947396
    Abstract: A negative electrode for a non-aqueous electrolyte secondary battery, which reversibly inserts/extracts lithium ions includes a current collector (11) in which a concave portion (12) and a convex portion (13) are formed at least one surface thereof; and a columnar body (15) which is formed by laminating n (n?2) stages of columnar body portions which are obliquely erected on the convex portion (13) of the current collector (11) and in which a content ratio of elements sequentially vary in a longitudinal direction of the current collector (11), and has a configuration in which variation directions of content ratios of elements of odd-numbered stages of columnar body portions and even-numbered stages of columnar body portions are different from each other. At least three surfaces (13a, 13b, 13c) of the convex portion (13) in a section of the longitudinal direction are covered by the columnar body portions.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: May 24, 2011
    Assignee: Panasonic Corporation
    Inventors: Masaya Ugaji, Masaki Hasegawa, Taisuke Yamamoto, Keisuke Ohara
  • Publication number: 20100190060
    Abstract: Having a current collector having a concave portion and a convex portion at least on one side, and a columnar body formed on the convex portion of the current collector, the columnar body contains an active material for inserting and extracting lithium ions bonding at least with oxygen, and the oxygen content ratio of the active material of the columnar body becomes smaller as going away from the interface of the current collector.
    Type: Application
    Filed: February 29, 2008
    Publication date: July 29, 2010
    Applicant: PANASONIC CORPORATION
    Inventors: Masaya Ugaji, Keisuke Ohara, Kazuhiro Watanabe
  • Publication number: 20100151320
    Abstract: A negative electrode for nonaqueous electrolyte secondary battery capable of reversible occlusion and release of lithium ions, comprising current collector (11) provided on at least one major surface thereof with depressed portion (12) and protrudent portion (13) and, superimposed on the protrudent portion (13) of the current collector (11), columnar body (15) composed of a laminate of n (n?2) layers of columnar body portions (16a,16b,16c) containing elements whose content ratio sequentially changes in the longitudinal direction of the current collector (11), wherein odd-numbered layers and even-numbered layers of the columnar body portions (16a,16b,16c) are different from each other in the direction of change of element content ratio.
    Type: Application
    Filed: September 21, 2007
    Publication date: June 17, 2010
    Inventors: Masaya Ugaji, Masaki Hasegawa, Taisuke Yamamoto, Keisuke Ohara
  • Publication number: 20100151330
    Abstract: A negative electrode for a non-aqueous electrolyte secondary battery, which reversibly inserts/extracts lithium ions includes a current collector (11) in which a concave portion (12) and a convex portion (13) are formed at least one surface thereof; and a columnar body (15) which is formed by laminating n (n?2) stages of columnar body portions which are obliquely erected on the convex portion (13) of the current collector (11) and in which a content ratio of elements sequentially vary in a longitudinal direction of the current collector (11), and has a configuration in which variation directions of content ratios of elements of odd-numbered stages of columnar body portions and even-numbered stages of columnar body portions are different from each other. At least three surfaces (13a, 13b, 13c) of the convex portion (13) in a section of the longitudinal direction are covered by the columnar body portions.
    Type: Application
    Filed: November 7, 2007
    Publication date: June 17, 2010
    Inventors: Masaya Ugaji, Masaki Hasegawa, Taisuke Yamamoto, Keisuke Ohara
  • Publication number: 20100119948
    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: Application
    Filed: April 11, 2008
    Publication date: May 13, 2010
    Inventors: Masaki Hasegawa, Masaya Ugaji, Keisuke Ohara, Hitoshi Matsumoto
  • Publication number: 20090280407
    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: Application
    Filed: December 26, 2007
    Publication date: November 12, 2009
    Inventors: Shuji Ito, Yasutaka Kogetsu, Kazuya Iwamoto, Kazuyoshi Honda, Taisuke Yamamoto, Yasuhiro Ueyama, Keisuke Ohara, Hitoshi Katayama
  • Publication number: 20090176158
    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: Application
    Filed: October 2, 2007
    Publication date: July 9, 2009
    Inventors: Masaya Ugaji, Masaki Hasegawa, Taisuke Yamamoto, Keisuke Ohara, Yasutaka Kogetsu, Takuhiro Nishimura