Patents by Inventor Yukihiro Oki

Yukihiro Oki 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: 8021787
    Abstract: The preservation performance of a nonaqueous electrolyte secondary cell charged to high potential is improved while the initial capacity and the cycle property of the cell are also improved. The nonaqueous electrolyte secondary cell includes: a positive electrode having lithium phosphate and a positive electrode active material containing lithium cobalt compound oxide and lithium manganese nickel compound oxide having a layer structure, the lithium cobalt compound oxide having at least zirconium and magnesium added in LiCoO2; a negative electrode having a negative electrode active material; and a nonaqueous electrolyte having a nonaqueous solvent and an electrolytic salt. The potential of the positive electrode is more than 4.3 V and 5.1 V or less based on lithium. The nonaqueous electrolyte contains vinylene carbonate as the nonaqueous solvent and, as the electrolytic salt, at least one of lithium bis(pentafluoroethane sulfonyl)imide and lithium bis(trifluoromethane sulfonyl)imide at 0.1 M or more and 0.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: September 20, 2011
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masato Iwanaga, Kentaro Takahashi, Yukihiro Oki, Yoshihiko Ikeda, Akira Kinoshita, Nobumichi Nishida
  • Patent number: 8021786
    Abstract: A non-aqueous electrolyte secondary cell superior in resistance against continuous charging at high potential is provided. The non-aqueous electrolyte secondary cell includes: a positive electrode having lithium phosphate and a positive electrode active material comprising lithium cobalt oxide containing at least one selected from Mg, Al, Ti, and Zr; and a separator having pores having an average diameter of 0.05 to 0.2 ?m.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: September 20, 2011
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Atsushi Kaiduka, Masato Iwanaga, Yukihiro Oki
  • Publication number: 20100233525
    Abstract: The nonaqueous electrolyte secondary battery includes a rolled electrode assembly 14E formed by rolling a positive electrode plate 11 and a negative electrode plate 12 with a separator 13 interposed therebetween, the separator 13 is fixed on the outermost periphery of the rolled electrode assembly 14E with an adhesive tape for fixing a roll end 30e, an exposed portion of a negative electrode substrate 12c without an active material mixture layer 12b is placed on an outermost periphery side of the negative electrode plate 12, a negative electrode tab 12a is connected to the negative electrode substrate 12c on an outermost periphery side, and the adhesive tape 30e is not overlapped with a roll end 11d of the positive electrode plate 11 and a roll end 12d of the negative electrode substrate 12c. Thus the battery is seldom broken even when charging and discharging are repeatedly provided at high voltage.
    Type: Application
    Filed: February 9, 2010
    Publication date: September 16, 2010
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Atsushi Kaiduka, Masanori Ogi, Yukihiro Oki, Masato Iwanaga
  • Publication number: 20090181311
    Abstract: The preservation performance of a nonaqueous electrolyte secondary cell charged to high potential is improved while the initial capacity and the cycle property of the cell are also improved. The nonaqueous electrolyte secondary cell includes: a positive electrode having lithium phosphate and a positive electrode active material containing lithium cobalt compound oxide and lithium manganese nickel compound oxide having a layer structure, the lithium cobalt compound oxide having at least zirconium and magnesium added in LiCoO2; a negative electrode having a negative electrode active material; and a nonaqueous electrolyte having a nonaqueous solvent and an electrolytic salt. The potential of the positive electrode is more than 4.3 V and 5.1 V or less based on lithium. The nonaqueous electrolyte contains vinylene carbonate as the nonaqueous solvent and, as the electrolytic salt, at least one of lithium bis(pentafluoroethane sulfonyl)imide and lithium bis(trifluoromethane sulfonyl)imide at 0.1 M or more and 0.
    Type: Application
    Filed: May 30, 2007
    Publication date: July 16, 2009
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Masato Iwanaga, Kentaro Takahashi, Yukihiro Oki, Yoshihiko Ikeda, Akira Kinoshita, Nobumichi Nishida
  • Publication number: 20080241694
    Abstract: A non-aqueous electrolyte secondary cell superior in resistance against continuous charging at high potential is provided. The non-aqueous electrolyte secondary cell includes: a positive electrode having lithium phosphate and a positive electrode active material comprising lithium cobalt oxide containing at least one selected from Mg, Al, Ti, and Zr; and a separator having pores having an average diameter of 0.05 to 0.2 ?m.
    Type: Application
    Filed: March 31, 2008
    Publication date: October 2, 2008
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Atsushi Kaiduka, Masato Iwanaga, Yukihiro Oki
  • Publication number: 20070172730
    Abstract: A nonaqueous electrolyte secondary battery of the invention has a positive electrode having a positive electrode active material, a negative electrode, and a nonaqueous electrolyte having electrolyte salt in a nonaqueous solvent. The electric potential of the positive electrode active material is 4.4 to 4.6 V relative to lithium, and the nonaqueous electrolyte contains a compound expressed by structural formula (I) below. The quantity of compound added is preferably 0.1% to 2% by mass. Also, the positive electrode active material preferably comprises a mixture of a lithium-cobalt composite oxide which is LiCoO2 containing at least both zirconium and magnesium and a lithium-manganese-nickel composite oxide that has a layer structure and contains at least both manganese and nickel. Thanks to such structure, a nonaqueous electrolyte secondary battery can be provided that is charged to charging termination potential of 4.4 to 4.6 V relative to lithium and that has enhanced overcharging safety.
    Type: Application
    Filed: January 23, 2007
    Publication date: July 26, 2007
    Applicants: SANYO ELECTRIC CO., LTD., UBE INDUSTRIES LTD.
    Inventors: Masato Iwanaga, Yukihiro Oki, Koji Abe, Kazuhiro Miyoshi