Patents by Inventor Kenji Nabekura

Kenji Nabekura 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: 7452633
    Abstract: A non-aqueous electrolyte secondary battery in which a positive electrode formed of a graphite powder and an negative electrode formed of a material capable of absorption/desorption of a lithium metal or lithium are placed to face each other in an electrolyte containing lithium salt. The positive electrode of this battery where a Lc (112) which is the size of crystallite in a c axis direction which is calculated from a (112) diffraction line of a graphite crystal and determined by a powder X-ray diffraction method which is from 4 nm to 30 nm, and a charge capacity at the first cycle which is calculated on the basis of a total weight of the graphite material of the positive electrode filled in the battery is 20 to 50 (mAh/g). Preferably, the graphite powder of the positive electrode has an ratio (A/B) which is the ratio of a specific surface area A determined by a nitrogen absorption (BET) method to a surface area B determined on the basis of an area average diameter of 20 or less.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: November 18, 2008
    Assignee: FDK Corporation
    Inventors: Takashi Suzuki, Toshiyuki Miwa, Hiroto Sagisaka, Kenji Nabekura, Masanori Nakanishi, Minoru Inagaki
  • Publication number: 20060292447
    Abstract: A non-aqueous electrolyte secondary battery in which a positive electrode formed of a graphite powder and an negative electrode formed of a material capable of absorption/desorption of a lithium metal or lithium are placed to face each other in an electrolyte containing lithium salt. The positive electrode of this battery where a Lc (112) which is the size of crystallite in a c axis direction which is calculated from a (112) diffraction line of a graphite crystal and determined by a powder X-ray diffraction method which is from 4 nm to 30 nm, and a charge capacity at the first cycle which is calculated on the basis of a total weight of the graphite material of the positive electrode filled in the battery is 20 to 50 (mAh/g). Preferably, the graphite powder of the positive electrode has an ratio (A/B) which is the ratio of a specific surface area A determined by a nitrogen absorption (BET) method to a surface area B determined on the basis of an area average diameter of 20 or less.
    Type: Application
    Filed: April 11, 2005
    Publication date: December 28, 2006
    Applicant: FDK CORPORATION
    Inventors: Takashi Suzuki, Toshiyuki Miwa, Hiroto Sagisaka, Kenji Nabekura, Masanori Nakanishi, Minoru Inagaki