Patents by Inventor Youshin Yagi

Youshin Yagi 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: 20130280571
    Abstract: A lithium ion secondary battery is disclosed in which an electrode assembly is accommodated in a battery container, the electrode assembly including a positive electrode having a positive electrode mixture layer containing a lithium transition metal composite oxide, a negative electrode having a negative electrode mixture layer for occluding/releasing lithium ions, and a separator disposed to inner and outer peripheries of the positive electrode and the negative electrode. The lithium ion secondary battery being charged with a non-aqueous electrolyte containing a lithium salt, wherein the relation shown by the following formula (I) is satisfied: 0.57<b×c/a<0.60??(I) assuming the area of the positive electrode mixture layer as a, the area of the separator as b, and the porosity of the separator as c.
    Type: Application
    Filed: December 15, 2011
    Publication date: October 24, 2013
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Takashi Eguchi, Katsunori Suzuki, Youshin Yagi
  • Patent number: 7659037
    Abstract: Using a positive electrode active material including spinel type manganese oxide as the main constituent, a novel low cost and high output power flat type nonaqueous secondary cell for HEVs that has increased safety at overcharge, and superior storage properties and cycle life is provided. A flat type nonaqueous secondary cell that has increased safety and is superior in storage and cycle properties even though the cell is a laminate type cell which does not have a blocking mechanism can be obtained by blending the spinel type lithium manganese oxide of the positive electrode and 5 wt % to 40 wt % of layered type lithium manganese oxide, to suppress storage deterioration at a high temperature and to simultaneously achieve safety when overcharged, and further, by adding a Li compound having a structure as shown in Formula (1) structure, to suppress deterioration of a mixed positive electrode active material during a high temperature cycle.
    Type: Grant
    Filed: December 13, 2006
    Date of Patent: February 9, 2010
    Assignees: Hitachi, Ltd., Hitachi Vehicle Energy, Ltd.
    Inventors: Hiroshi Fukunaga, Youshin Yagi, Shuichi Wada, Kenji Hara, Kazushige Kohno, Hiroshi Haruna
  • Publication number: 20070134558
    Abstract: Using a positive electrode active material including spinel type manganese oxide as the main constituent, a novel low cost and high output power flat type nonaqueous secondary cell for HEVs that has increased safety at overcharge, and superior storage properties and cycle life is provided. A flat type nonaqueous secondary cell that has increased safety and is superior in storage and cycle properties even though the cell is a laminate type cell which does not have a blocking mechanism can be obtained by blending the spinel type lithium manganese oxide of the positive electrode and 5 wt % to 40 wt % of layered type lithium manganese oxide, to suppress storage deterioration at a high temperature and to simultaneously achieve safety when overcharged, and further, by adding a Li compound having a structure as shown in Formula (1) structure, to suppress deterioration of a mixed positive electrode active material during a high temperature cycle.
    Type: Application
    Filed: December 13, 2006
    Publication date: June 14, 2007
    Inventors: Hiroshi Fukunaga, Youshin Yagi, Shuichi Wada, Konji Hara, Kazushige Kohno, Hiroshi Haruna
  • Patent number: 6803149
    Abstract: The present invention is to provide a non-aqueous electrolytic solution secondary battery which has high safety while maintaining high capacity and high power. A cylindrical lithium-ion battery 20 is provided in a battery lid which is a portion of a battery container with a cleavage valve 11 which cleaves at a predetermined pressure, and includes an electrode winding group 6 prepared by winding a positive electrode, a negative electrode and a separator, connection portions for connecting the electrode winding group 6 to respective electrode terminals, and non-aqueous electrolytic solution therein. As a positive electrode active material, lithium manganate where the amount of elution of manganese into the non-aqueous electrolytic solution is 5% or less based on the lithium manganate in a region where an electrode potential to metal lithium is 4.8V or more is used. As a negative electrode active material, graphite in/from which lithium ions can be occluded/released according to charging and discharging is used.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: October 12, 2004
    Assignee: Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Kenji Nakai, Yoshimasa Koishikawa, Youshin Yagi, Kensuke Hironaka
  • Patent number: 6706446
    Abstract: A cylindrical lithium-ion battery 20 accommodates a winding group 6, is structured by winding a positive electrode using lithium manganate (Li1+xMn2−xO4 or Li1+xMn2−x−yAlyO4) having an average particle diameter of primary particles in a range of from 0.1 &mgr;m to 2 &mgr;m as a positive electrode active material and a negative electrode using amorphous carbon as a negative electrode active material via a separator, and a non-aqueous electrolytic solution within a battery container 7.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: March 16, 2004
    Assignee: Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Kenji Nakai, Yoshimasa Koishikawa, Yuichi Takatsuka, Kensuke Hironaka, Takeshi Nakano, Youshin Yagi
  • Publication number: 20020122983
    Abstract: The present invention provides a lithium-ion secondary battery whose power characteristic has been improved without widening a battery size. A cylindrical lithium-ion battery 20 accommodates a winding group 6 and a non-aqueous electrolytic solution within a battery container 7. The winding group 6 is structured by winding a positive electrode using lithium manganate (Li1+xMn2−xO4 or Li1+xMn2−x−yAlyO4) where an average particle diameter of primary particles is in a range of from 0.1 &mgr;m to 2 &mgr;m as a positive electrode active material and a negative electrode using amorphous carbon as a negative electrode active material via a separator. The reaction area of the positive electrode active material is optimized.
    Type: Application
    Filed: October 16, 2001
    Publication date: September 5, 2002
    Applicant: SHIN-KOBE ELECTRIC MACHINERY CO., LTD.
    Inventors: Kenji Nakai, Yoshimasa Koishikawa, Yuichi Takatsuka, Kensuke Hironaka, Takeshi Nakano, Youshin Yagi
  • Publication number: 20020102460
    Abstract: The present invention is to provide a non-aqueous electrolytic solution secondary battery which has high safety while maintaining high capacity and high power. A cylindrical lithium-ion battery 20 is provided in a battery lid which is a portion of a battery container with a cleavage valve 11 which cleaves at a predetermined pressure, and includes an electrode winding group 6 prepared by winding a positive electrode, a negative electrode and a separator, connection portions for connecting the electrode winding group 6 to respective electrode terminals, and non-aqueous electrolytic solution therein. As a positive electrode active material, lithium manganate where the amount of elution of manganese into the non-aqueous electrolytic solution is 5% or less based on the lithium manganate in a region where an electrode potential to metal lithium is 4.8V or more is used. As a negative electrode active material, graphite in/from which lithium ions can be occluded/released according to charging and discharging is used.
    Type: Application
    Filed: October 16, 2001
    Publication date: August 1, 2002
    Applicant: SHIN-KOBE ELECTRIC MACHINERY CO., LTD.
    Inventors: Kenji Nakai, Yoshimasa Koishikawa, Youshin Yagi, Kensuke Hironaka