Patents by Inventor Rika Yatabe

Rika Yatabe 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: 11515517
    Abstract: A positive electrode for a nonaqueous secondary battery including an active material layer which has sufficient electron conductivity with a low ratio of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery including an active material layer which is highly filled with an active material, id est, including the active material and a low ratio of a conductive additive. The active material layer includes a plurality of particles of an active material with a layered rock salt structure, graphene that is in surface contact with the plurality of particles of the active material, and a binder.
    Type: Grant
    Filed: December 11, 2019
    Date of Patent: November 29, 2022
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takahiro Kawakami, Masaki Yamakaji, Mako Motoyoshi, Rika Yatabe
  • Patent number: 11108038
    Abstract: A positive electrode for a secondary battery which enables both good battery characteristics and electrode strength at a predetermined level, a secondary battery, and a method for fabricating the positive electrode for a secondary battery are provided. The positive electrode for a secondary battery includes a current collector and an active material layer over the current collector. The active material layer includes an active material, graphene, and a binder. A carbon layer is on a surface of the active material. The proportion of the graphene in the active material layer is greater than or equal to 0.1 wt % and less than or equal to 1.0 wt %.
    Type: Grant
    Filed: June 27, 2016
    Date of Patent: August 31, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masaki Yamakaji, Takahiro Kawakami, Mako Motoyoshi, Rika Yatabe
  • Patent number: 10593940
    Abstract: A power storage device having high capacitance is provided. A power storage device with excellent cycle characteristics is provided. A power storage device with high charge and discharge efficiency is provided. A power storage device including a negative electrode with low resistance is provided. A negative electrode for the power storage device includes a current collector and an active material layer including a plurality of active material particles over the current collector. The active material particle is silicon, and the size of the silicon particle is greater than or equal to 0.001 ?m and less than or equal to 7 ?m.
    Type: Grant
    Filed: July 2, 2018
    Date of Patent: March 17, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Kiyofumi Ogino, Yumiko Yoneda, Rika Yatabe, Nobuhiro Inoue
  • Publication number: 20190067701
    Abstract: A graphene oxide used as a raw material of a conductive additive for forming an active material layer with high electron conductivity with a small amount of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery using the graphene oxide as a conductive additive is provided. The graphene oxide is used as a raw material of a conductive additive in a positive electrode for a nonaqueous secondary battery and, in the graphene oxide, the atomic ratio of oxygen to carbon is greater than or equal to 0.405.
    Type: Application
    Filed: October 25, 2018
    Publication date: February 28, 2019
    Inventors: Hiroatsu Todoriki, Mikio Yukawa, Yumiko Saito, Masaki Yamakaji, Rika Yatabe, Tatsuya Ikenuma
  • Patent number: 10128529
    Abstract: A lithium-ion secondary battery with a high capacity retention rate is provided. In addition, a fabricating method of a lithium-ion secondary battery with a high capacity retention rate is provided. The lithium-ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte solution. The negative electrode includes a negative electrode active material layer. The electrolyte solution includes at least one of lithium bis(trifluoromethanesulfonyl)amide (LiTFSA) and lithium bis(fluorosulfonyl)amide (LiFSA). The electrolyte solution includes vinylene carbonate (VC). A coating film including lithium oxide is on a surface of the negative electrode active material layer.
    Type: Grant
    Filed: November 9, 2016
    Date of Patent: November 13, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Ai Nakagawa, Teppei Oguni, Kai Kimura, Rika Yatabe
  • Patent number: 9768443
    Abstract: A positive electrode for a nonaqueous secondary battery including an active material layer which has sufficient electron conductivity with a low ratio of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery including an active material layer which is highly filled with an active material, id est, including the active material and a low ratio of a conductive additive. The active material layer includes a plurality of particles of an active material with a layered rock salt structure, graphene that is in surface contact with the plurality of particles of the active material, and a binder.
    Type: Grant
    Filed: November 4, 2013
    Date of Patent: September 19, 2017
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takahiro Kawakami, Masaki Yamakaji, Mako Motoyoshi, Rika Yatabe
  • Patent number: 9385366
    Abstract: A positive electrode for a secondary battery which enables both good battery characteristics and electrode strength at a predetermined level, a secondary battery, and a method for fabricating the positive electrode for a secondary battery are provided. The positive electrode for a secondary battery includes a current collector and an active material layer over the current collector. The active material layer includes an active material, graphene, and a binder. A carbon layer is on a surface of the active material. The proportion of the graphene in the active material layer is greater than or equal to 0.1 wt % and less than or equal to 1.0 wt %.
    Type: Grant
    Filed: August 22, 2013
    Date of Patent: July 5, 2016
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masaki Yamakaji, Takahiro Kawakami, Mako Motoyoshi, Rika Yatabe
  • Patent number: 9373834
    Abstract: To provide a positive electrode for a lithium-ion secondary battery, which is highly filled with a positive electrode active material and has a high-density positive electrode active material layer. To provide a lithium-ion secondary battery having high capacity and improved cycle characteristics with use of the positive electrode. After graphene oxide is dispersed in a dispersion medium, a positive electrode active material is added and mixed to form a mixture. A binder is added to the mixture and mixed to form a positive electrode paste. The positive electrode paste is applied to a positive electrode current collector and the dispersion medium contained in the positive electrode paste is evaporated, and then, the graphene oxide is reduced, so that a positive electrode active material layer containing graphene is formed over the positive electrode current collector.
    Type: Grant
    Filed: December 11, 2012
    Date of Patent: June 21, 2016
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masaki Yamakaji, Rika Yatabe, Hiroatsu Todoriki
  • Patent number: 9293770
    Abstract: A graphene oxide used as a raw material of a conductive additive for forming an active material layer with high electron conductivity with a small amount of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery using the graphene oxide as a conductive additive is provided. The graphene oxide is used as a raw material of a conductive additive in a positive electrode for a nonaqueous secondary battery and, in the graphene oxide, the atomic ratio of oxygen to carbon is greater than or equal to 0.405.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: March 22, 2016
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Hiroatsu Todoriki, Mikio Yukawa, Yumiko Saito, Masaki Yamakaji, Rika Yatabe, Tatsuya Ikenuma
  • Publication number: 20140127568
    Abstract: A positive electrode for a nonaqueous secondary battery including an active material layer which has sufficient electron conductivity with a low ratio of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery including an active material layer which is highly filled with an active material, id est, including the active material and a low ratio of a conductive additive. The active material layer includes a plurality of particles of an active material with a layered rock salt structure, graphene that is in surface contact with the plurality of particles of the active material, and a binder.
    Type: Application
    Filed: November 4, 2013
    Publication date: May 8, 2014
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takahiro KAWAKAMI, Masaki Yamakaji, Mako Motoyoshi, Rika Yatabe
  • Publication number: 20140057165
    Abstract: A positive electrode for a secondary battery which enables both good battery characteristics and electrode strength at a predetermined level, a secondary battery, and a method for fabricating the positive electrode for a secondary battery are provided. The positive electrode for a secondary battery includes a current collector and an active material layer over the current collector. The active material layer includes an active material, graphene, and a binder. A carbon layer is on a surface of the active material. The proportion of the graphene in the active material layer is greater than or equal to 0.1 wt % and less than or equal to 1.0 wt %.
    Type: Application
    Filed: August 22, 2013
    Publication date: February 27, 2014
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masaki YAMAKAJI, Takahiro Kawakami, Mako Motoyoshi, Rika Yatabe