Patents by Inventor Mariko Kohmoto

Mariko Kohmoto 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: 9225022
    Abstract: The positive active material is a positive active material for a lithium secondary battery, including a lithium transition metal compound that has an olivine crystal structure and contains at least Ni, Fe, and Mn as transition metal elements, wherein when the sum of mole atoms of Ni, Fe, and Mn of transition metal elements contained in the lithium transition metal compound is expressed as 1, and the mole atomic ratios of Ni, Fe, and Mn are represented by a, b, and c (a+b+c=1, a>0, b>0, c>0), respectively, the following is satisfied: 0.85?c?0.92 and 0.3?a/(a+b)?0.9.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: December 29, 2015
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Mariko Kohmoto, Toru Tabuchi, Tokuo Inamasu, Toshiyuki Nukuda
  • Patent number: 8663847
    Abstract: It is an object of the present invention to provide a positive electrode material having a large ratio of the discharge capacity around 4 V to the total discharge capacity including the discharge capacity at 4V or lower while making the discharge capacity around 4 V sufficient, for the purpose of providing a lithium secondary battery using a lithium transition metal phosphate compound excellent in thermal stability, utilizing the discharge potential around 4V (vs. Li/Li+) that is higher than the discharge potential of LiFePO4, and being advantageous with respect to the detection of the end of discharge state, and a lithium secondary battery using the same. The present invention uses a positive active material for a lithium secondary battery containing a lithium transition metal phosphate compound represented by LiMn1-x-yFexCoyPO4(0.1?x?0.2, 0<y?0.2).
    Type: Grant
    Filed: November 27, 2009
    Date of Patent: March 4, 2014
    Assignee: GS Yuasa International Ltd.
    Inventors: Yuta Kashiwa, Mariko Kohmoto, Toru Tabuchi, Tokuo Inamasu, Toshiyuki Nukuda
  • Patent number: 8431271
    Abstract: The invention provides a polyanion-based positive active material which can improve storage stability (especially, high temperature storage stability), charge and discharge cycle performance and the like of a lithium secondary battery, and a lithium secondary battery using the same. The positive active material for a lithium ion secondary battery contains lithium iron cobalt phosphate represented by the general formula: LiyFe(1-x)CoxPO4(0<x?0.019, 0?y?1.2). By using the positive active material for a lithium secondary battery, high temperature storage stability and charge and discharge cycle performance can be improved in comparison with a case where LiyFePO4 containing no Co is used. By using the positive active material, a lithium ion secondary battery can be suitable for applications in fields of electric automobiles and industrial batteries in which long lives, high capacities, and high output powers are required.
    Type: Grant
    Filed: May 22, 2009
    Date of Patent: April 30, 2013
    Assignee: GS Yuasa International Ltd.
    Inventors: Yukiko Fujino, Yoshinobu Yasunaga, Akihiro Fujii, Yohei Shibata, Mariko Kohmoto, Takashi Egawa, Toru Tabuchi, Hiroe Nakagawa, Tokuo Inamasu, Toshiyuki Nukuda
  • Publication number: 20120028122
    Abstract: The positive active material is a positive active material for a lithium secondary battery, including a lithium transition metal compound that has an olivine crystal structure and contains at least Ni, Fe, and Mn as transition metal elements, wherein when the sum of mole atoms of Ni, Fe, and Mn of transition metal elements contained in the lithium transition metal compound is expressed as 1, and the mole atomic ratios of Ni, Fe, and Mn are represented by a, b, and c (a+b+c=1, a>0, b>0, c>0), respectively, the following is satisfied: 0.85?c?0.92 and 0.3?a/(a+b)?0.9.
    Type: Application
    Filed: June 16, 2010
    Publication date: February 2, 2012
    Applicant: GS YUASA INTERNATIONAL LTD.
    Inventors: Mariko Kohmoto, Toru Tabuchi, Tokuo Inamasu, Toshiyuki Nukuda
  • Publication number: 20110274975
    Abstract: It is an object of the present invention to provide a positive electrode material having a large ratio of the discharge capacity around 4 V to the total discharge capacity including the discharge capacity at 4V or lower while making the discharge capacity around 4 V sufficient, for the purpose of providing a lithium secondary battery using a lithium transition metal phosphate compound excellent in thermal stability, utilizing the discharge potential around 4V (vs. Li/Li+) that is higher than the discharge potential of LiFePO4, and being advantageous with respect to the detection of the end of discharge state, and a lithium secondary battery using the same. The present invention uses a positive active material for a lithium secondary battery containing a lithium transition metal phosphate compound represented by LiMn1-x-yFexCoyPO4 (0.1?x?0.2, 0<y?0.2).
    Type: Application
    Filed: November 27, 2009
    Publication date: November 10, 2011
    Applicant: GS YUASA INTERNATIONAL LTD.
    Inventors: Yuta Kashiwa, Mariko Kohmoto, Toru Tabuchi, Tokuo Inamasu, Toshiyuki Nukuda
  • Publication number: 20110068293
    Abstract: The invention provides a polyanion-based positive active material which can improve storage stability (especially, high temperature storage stability), charge and discharge cycle performance and the like of a lithium secondary battery, and a lithium secondary battery using the same. The positive active material for a lithium ion secondary battery contains lithium iron cobalt phosphate represented by the general formula: LiyFe(1-x)CoxPO4 (0<x?0.019, 0?y?1.2). By using the positive active material for a lithium secondary battery, high temperature storage stability and charge and discharge cycle performance can be improved in comparison with a case where LiyFePO4 containing no Co is used. By using the positive active material, a lithium ion secondary battery can be suitable for applications in fields of electric automobiles and industrial batteries in which long lives, high capacities, and high output powers are required.
    Type: Application
    Filed: May 22, 2009
    Publication date: March 24, 2011
    Applicant: GS YUASA INTERNATIONAL LTD.
    Inventors: Yukiko Fujino, Yoshinobu Yasunaga, Akihiro Fujii, Yohei Shibata, Mariko Kohmoto, Takashi Egawa, Toru Tabuchi, Hiroe Nakagawa, Tokuo Inamasu, Toshiyuki Nukuda
  • Publication number: 20100086855
    Abstract: An object is to provide a positive electrode material capable of increasing a discharge capacity of a nonaqueous electrolyte secondary battery, a production method thereof, and the like.
    Type: Application
    Filed: July 16, 2009
    Publication date: April 8, 2010
    Applicant: GS YUASA CORPORATION
    Inventors: Mariko Kohmoto, Toru Tabuchi, Tokuo Inamasu, Toshio Murata