Patents by Inventor Junji Akimoto

Junji Akimoto 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: 20210013495
    Abstract: A multilayer body is provided that is used as the negative electrode of a lithium-ion secondary battery that has a high capacity and is excellent in terms of safety, economic efficiency, and cycle characteristics. The multilayer body has a conductive substrate and a composite layer provided on the conductive substrate. The composite layer includes a plurality of particles of silicon oxide and a conductive substance present in gaps between the plurality of particles of silicon oxide. The average particle diameter of the particles of silicon oxide is 1.0 ?m or less. The multilayer body further has a conductive layer that is provided on the composite layer and contains a conductive substance. The conductive layer has a thickness of 20 ?m or less.
    Type: Application
    Filed: February 22, 2019
    Publication date: January 14, 2021
    Inventors: Mikito MAMIYA, Junji AKIMOTO
  • Patent number: 10807878
    Abstract: Provided is a complex oxide that has a space group I-43d, has a high hydrogen content, contains almost no impurity phase, exhibits almost no aluminum substitution in the structure thereof, and is suitable for proton conductivity. This complex oxide is represented by a chemical formula Li7-x-yHxLa3Zr2-yMyO12 (M represents Ta and/or Nb, 3.2<x?7?y, and 0.25<y<2) and is a single phase of a garnet type structure belonging to a cubic system, and the crystal structure thereof is a space group I-43d.
    Type: Grant
    Filed: August 19, 2016
    Date of Patent: October 20, 2020
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Junji Akimoto, Naoki Hamao, Kunimitsu Kataoka
  • Publication number: 20200303771
    Abstract: To provide a lithium ion conductive crystal body having a high density and a large length and an all-solid state lithium ion secondary battery containing the lithium ion conductive crystal body. A Li5La3Ta2O12 crystal body, which is one example of the lithium ion conductive crystal body, has a relative density of 99% or more, belongs to a cubic system, has a garnet-related type structure, and has a length of 2 cm or more. The Li5La3Ta2O12 crystal body is grown by a melting method employing a Li5La3Ta2O12 polycrystal body as a raw material. With the growing method, a Li5La3Ta2O12 crystal body having a relative density of 100% can also be obtained. In addition, the all-solid state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, in which the solid electrolyte contains the lithium ion conductive crystal body.
    Type: Application
    Filed: June 9, 2020
    Publication date: September 24, 2020
    Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Kunimitsu KATAOKA, Junji AKIMOTO
  • Patent number: 10763544
    Abstract: A solid electrolyte material having high ion conductivity and a all-solid-state lithium-ion secondary battery using this solid electrolyte material are provided. The solid electrolyte material has a garnet-related structure crystal represented by the chemical composition Li7?x?yLa3Zr2?x?yTaxNbyO12 (0.05?x+y?0.2, x?0, y?0), which belongs to an orthorhombic system and a space group belonging to Ibca. The solid electrolyte material has lithium-ion conductivity at 25° C. of at least 1.0×10?4 S/cm. Also, in this solid electrolyte material, the lattice constants are 1.29 nm?a?1.32 nm, 1.26 nm?b?1.29 nm, and 1.29 nm?c?1.32 nm, and three 16f sites and one 8d site in the crystal structure are occupied by lithium-ions. The all-solid-state lithium-ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, the solid electrolyte comprising this solid electrolyte material.
    Type: Grant
    Filed: May 2, 2017
    Date of Patent: September 1, 2020
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Naoki Hamao, Kunimitsu Kataoka, Junji Akimoto
  • Publication number: 20200274193
    Abstract: A solid electrolyte material having high ion conductivity and a all-solid-state lithium-ion secondary battery using this solid electrolyte material are provided. The solid electrolyte material has a garnet-related structure crystal represented by the chemical composition Li7?x?yLa3Zr2?x?yTaxNbyO12 (0.05?x+y?0.2, x?0, y?0), which belongs to an orthorhombic system and a space group belonging to Ibca. The solid electrolyte material has lithium-ion conductivity at 25° C. of at least 1.0×10?4 S/cm. Also, in this solid electrolyte material, the lattice constants are 1.29 nm?a?1.32 nm, 1.26 nm?b?1.29 nm, and 1.29 nm?c?1.32 nm, and three 16f sites and one 8d site in the crystal structure are occupied by lithium-ions. The all-solid-state lithium-ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, the solid electrolyte comprising this solid electrolyte material.
    Type: Application
    Filed: May 2, 2017
    Publication date: August 27, 2020
    Applicant: National Institute of Advanced Industrial Science and Technology
    Inventors: Naoki HAMAO, Kunimitsu KATAOKA, Junji AKIMOTO
  • Patent number: 10693184
    Abstract: Provided is a high-density lithium-containing garnet crystal body. The lithium-containing garnet crystal body has a relative density of 99% or more, belongs to a tetragonal system, and has a garnet-related type structure. A method of producing a Li7La3Zr2O12 crystal, which is one example of this lithium-containing garnet crystal body, includes melting a portion of a rod-like raw material composed of polycrystalline Li7La3Zr2O12 belonging to a tetragonal system while rotating it on a plane perpendicular to the longer direction and moving the melted portion in the longer direction. The moving rate of the melted portion is preferably 8 mm/h or more but not more than 19 mm/h. The rotational speed of the raw material is preferably 30 rpm or more but not more than 60 rpm. By increasing the moving rate of the melted portion, decomposition of the raw material due to evaporation of lithium can be prevented and by increasing the rotational speed of the raw material, air bubbles can be removed.
    Type: Grant
    Filed: July 30, 2015
    Date of Patent: June 23, 2020
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Kunimitsu Kataoka, Junji Akimoto
  • Patent number: 10669159
    Abstract: Provided is a complex oxide that has a high hydrogen content, contains almost no impurity phase, and is suitable for proton conductivity. The complex oxide is represented by a chemical formula Li7-xHxLa3M2O12 (M represents Zr and/or Hf, and 3.2<x?7) and is a single phase of a garnet type structure belonging to a cubic system. A method for producing the complex oxide includes an exchange step of bringing a raw material complex oxide represented by a chemical formula Li7-xHxLa3M2O12 (M represents Zr and/or Hf, and 0?x?3.2) and a compound having a hydroxy group or a carboxyl group into contact with each other to exchange at least some of lithium of the raw material complex oxide and hydrogen of the compound having a hydroxy group or a carboxyl group.
    Type: Grant
    Filed: August 19, 2016
    Date of Patent: June 2, 2020
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Junji Akimoto, Naoki Hamao, Kunimitsu Kataoka
  • Patent number: 10566655
    Abstract: There are provided a solid electrolyte material having high density and ion conductivity, and an all solid lithium ion secondary battery using the solid electrolyte material. The solid electrolyte material has a garnet-related structure which has a chemical composition represented by Li7-x-yLa3Zr2-x-yTaxNbyO12 (0?x?0.8, 0.2?y?1, and 0.2?x+y?1) and relative density of 99% or greater, and belongs to a cubic system. The solid electrolyte material has lithium ion conductivity which is equal to or greater than 1.0×10?3 S/cm. The solid electrolyte material has a lattice constant a which satisfies 1.28 nm?a?1.30 nm, and has a lithium ion which occupies only two or more 96h sites in a crystal structure. The all solid lithium ion secondary battery includes a positive electrode, a negative electrode, and a solid electrolyte. The solid electrolyte includes the solid electrolyte material.
    Type: Grant
    Filed: December 26, 2016
    Date of Patent: February 18, 2020
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Kunimitsu Kataoka, Chika Takamori, Haruo Ishizaki, Junji Akimoto
  • Patent number: 10505189
    Abstract: A composite oxide which includes lithium, at least one of calcium and magnesium, and nickel and manganese, and has a lithium-excess layered rock-salt structure, and a cathode active material and a lithium secondary battery which contain the composite oxide.
    Type: Grant
    Filed: May 20, 2016
    Date of Patent: December 10, 2019
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Junji Akimoto, Hiroshi Hayakawa
  • Publication number: 20190341651
    Abstract: There are provided a solid electrolyte material having high density and ion conductivity, and an all solid lithium ion secondary battery using the solid electrolyte material. The solid electrolyte material has a garnet-related structure which has a chemical composition represented by Li7-x-yLa3Zr2-x-yTaxNbyO12 (0?x?0.8, 0.2?y?1, and 0.2?x+y?1) and relative density of 99% or greater, and belongs to a cubic system. The solid electrolyte material has lithium ion conductivity which is equal to or greater than 1.0×10?3 S/cm. The solid electrolyte material has a lattice constant a which satisfies 1.28 nm?a?1.30 nm, and has a lithium ion which occupies only two or more 96h sites in a crystal structure. The all solid lithium ion secondary battery includes a positive electrode, a negative electrode, and a solid electrolyte. The solid electrolyte includes the solid electrolyte material.
    Type: Application
    Filed: December 26, 2016
    Publication date: November 7, 2019
    Applicant: National Institute of Advanced Industrial Science and Technology
    Inventors: Kunimitsu KATAOKA, Chika TAKAMORI, Haruo ISHIZAKI, Junji AKIMOTO
  • Patent number: 10347912
    Abstract: Provided are a sodium ion secondary battery and a lithium ion secondary battery capable of undergoing a reversible large-capacity charge/discharge reaction. The sodium and lithium ion secondary batteries each have a positive electrode, a negative electrode, and an electrolyte. The active substance of the positive or negative electrode of these secondary batteries is a single-phase polycrystal represented by the following chemical formula: NaxTi4O9 (2?x?3), preferably Na2Ti4O9, having a one-dimensional tunnel type structure, and belonging to a monoclinic crystal system. This polycrystal is obtained by filling a container made of molybdenum or the like with a raw material containing a sodium compound and at least one of a titanium compound and metal titanium, and firing at 800° C. or more but 1600° C. or less.
    Type: Grant
    Filed: August 6, 2015
    Date of Patent: July 9, 2019
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Kunimitsu Kataoka, Junji Akimoto
  • Patent number: 10319985
    Abstract: There are provided a lithium-containing garnet crystal high in density and ionic conductivity, and an all-solid-state lithium ion secondary battery using the lithium-containing garnet crystal. The lithium-containing garnet crystal has a chemical composition represented by Li7-xLa3Zr2-xTaxO12 (0.2?x?1), and has a relative density of 99% or higher, belongs to a cubic system, and has a garnet-related structure. The lithium-containing garnet crystal has a lithium ion conductivity of 1.0×10?3 S/cm or higher. Further, this solid electrolyte material has a lattice constant a of 1.28 nm?a?1.30 nm, and lithium ions occupy 96h-sites in the crystal structure. The all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode and a solid electrolyte, and the solid electrolyte is constituted of the lithium-containing garnet crystal according to the present invention.
    Type: Grant
    Filed: October 23, 2015
    Date of Patent: June 11, 2019
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Kunimitsu Kataoka, Junji Akimoto
  • Publication number: 20180282174
    Abstract: Provided is a complex oxide that has a high hydrogen content, contains almost no impurity phase, and is suitable for proton conductivity. The complex oxide is represented by a chemical formula Li7-xHxLa3M2O12 (M represents Zr and/or Hf, and 3.2<x?7) and is a single phase of a garnet type structure belonging to a cubic system. A method for producing the complex oxide includes an exchange step of bringing a raw material complex oxide represented by a chemical formula Li7-xHxLa3M2O12 (M represents Zr and/or Hf, and 0?x?3.2) and a compound having a hydroxy group or a carboxyl group into contact with each other to exchange at least some of lithium of the raw material complex oxide and hydrogen of the compound having a hydroxy group or a carboxyl group.
    Type: Application
    Filed: August 19, 2016
    Publication date: October 4, 2018
    Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Junji AKIMOTO, Naoki HAMAO, Kunimitsu KATAOKA
  • Publication number: 20180179080
    Abstract: Provided is a complex oxide that has a space group I-43d, has a high hydrogen content, contains almost no impurity phase, exhibits almost no aluminum substitution in the structure thereof, and is suitable for proton conductivity. This complex oxide is represented by a chemical formula Li7-x-yHxLa3Zr2-yMyO12 (M represents Ta and/or Nb, 3.2<x?7-y, and 0.25<y<2) and is a single phase of a garnet type structure belonging to a cubic system, and the crystal structure thereof is a space group I-43d.
    Type: Application
    Filed: August 19, 2016
    Publication date: June 28, 2018
    Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Junji AKIMOTO, Naoki HAMAO, Kunimitsu KATAOKA
  • Publication number: 20180138507
    Abstract: A composite oxide which includes lithium, at least one of calcium and magnesium, and nickel and manganese, and has a lithium-excess layered rock-salt structure, and a cathode active material and a lithium secondary battery which contain the composite oxide.
    Type: Application
    Filed: May 20, 2016
    Publication date: May 17, 2018
    Inventors: Junji AKIMOTO, Hiroshi HAYAKAWA
  • Patent number: 9856148
    Abstract: Provided are: an alkali metal titanium oxide having a uniform composition and that is such that there are no residual by-products having a different composition or unreacted starting materials; and a method for producing a titanium oxide and proton exchange body obtained by processing the alkali metal titanium oxide. The method produces an alkali metal titanium oxide by firing the result of impregnating the surface and inside of pores of porous titanium compound particles with an aqueous solution of an alkali metal-containing component. The alkali metal titanium oxide is subjected to proton exchange, and with the proton exchange body of the alkali metal titanium oxide as the starting material, the titanium oxide is produced through a heat processing step.
    Type: Grant
    Filed: August 14, 2014
    Date of Patent: January 2, 2018
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, ISHIHARA SANGYO KAISHA, LTD.
    Inventors: Hideaki Nagai, Junji Akimoto, Kunimitsu Kataoka, Yoshimasa Kumashiro, Tomoyuki Sotokawa, Nobuharu Koshiba
  • Publication number: 20170365847
    Abstract: Provided are a sodium ion secondary battery and a lithium ion secondary battery capable of undergoing a reversible large-capacity charge/discharge reaction. The sodium and lithium ion secondary batteries each have a positive electrode, a negative electrode, and an electrolyte. The active substance of the positive or negative electrode of these secondary batteries is a single-phase polycrystal represented by the following chemical formula: NaxTi4O9 (2?x?3), preferably Na2Ti4O9, having a one-dimensional tunnel type structure, and belonging to a monoclinic crystal system. This polycrystal is obtained by filling a container made of molybdenum or the like with a raw material containing a sodium compound and at least one of a titanium compound and metal titanium, and firing at 800° C. or more but 1600° C. or less.
    Type: Application
    Filed: August 6, 2015
    Publication date: December 21, 2017
    Inventors: Kunimitsu KATAOKA, Junji AKIMOTO
  • Publication number: 20170324079
    Abstract: There are provided a lithium-containing garnet crystal high in density and ionic conductivity, and an all-solid-state lithium ion secondary battery using the lithium-containing garnet crystal. The lithium-containing garnet crystal has a chemical composition represented by Li7-xLa3Zr2-xTaxO12 (0.2?x?1), and has a relative density of 99% or higher, belongs to a cubic system, and has a garnet-related structure. The lithium-containing garnet crystal has a lithium ion conductivity of 1.0×10?3 S/cm or higher. Further, this solid electrolyte material has a lattice constant a of 1.28 nm?a?1.30 nm, and lithium ions occupy 96h-sites in the crystal structure. The all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode and a solid electrolyte, and the solid electrolyte is constituted of the lithium-containing garnet crystal according to the present invention.
    Type: Application
    Filed: October 23, 2015
    Publication date: November 9, 2017
    Inventors: Kunimitsu KATAOKA, Junji AKIMOTO
  • Publication number: 20170309955
    Abstract: To provide a lithium ion conductive crystal body having a high density and a large length and an all-solid state lithium ion secondary battery containing the lithium ion conductive crystal body. A Li5La3Ta2O12 crystal body, which is one example of the lithium ion conductive crystal body, has a relative density of 99% or more, belongs to a cubic system, has a garnet-related type structure, and has a length of 2 cm or more. The Li5La3Ta2O12 crystal body is grown by a melting method employing a Li5La3Ta2O12 polycrystal body as a raw material. With the growing method, a Li5La3Ta2O12 crystal body having a relative density of 100% can also be obtained. In addition, the all-solid state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, in which the solid electrolyte contains the lithium ion conductive crystal body.
    Type: Application
    Filed: October 30, 2015
    Publication date: October 26, 2017
    Applicant: National Institute of Advanced Industrial Science and Technology
    Inventors: Kunimitsu KATAOKA, Junji AKIMOTO
  • Publication number: 20170222258
    Abstract: Provided is a high-density lithium-containing garnet crystal body. The lithium-containing garnet crystal body has a relative density of 99% or more, belongs to a tetragonal system, and has a garnet-related type structure. A method of producing a Li7La3Zr2O12 crystal, which is one example of this lithium-containing garnet crystal body, includes melting a portion of a rod-like raw material composed of polycrystalline Li7La3Zr2O12 belonging to a tetragonal system while rotating it on a plane perpendicular to the longer direction and moving the melted portion in the longer direction. The moving rate of the melted portion is preferably 8 mm/h or more but not more than 19 mm/h. The rotational speed of the raw material is preferably 30 rpm or more but not more than 60 rpm. By increasing the moving rate of the melted portion, decomposition of the raw material due to evaporation of lithium can be prevented and by increasing the rotational speed of the raw material, air bubbles can be removed.
    Type: Application
    Filed: July 30, 2015
    Publication date: August 3, 2017
    Inventors: Kunimitsu KATAOKA, Junji AKIMOTO