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: 20240327237
    Abstract: The invention provides a secondary battery positive electrode active material including an oxide containing Li, Mn, and Ti, wherein the oxide has a Li content of 43 to 60 mol %, a Mn content of 22 to 35 mol %, and a Ti content of 7 to 29 mol %, the oxide has an X-ray diffraction pattern that is measured using CuK? as an X-ray source and has a maximum X-ray diffraction peak exhibiting the highest peak intensity and existing at an angle in the range of 43 to 45 degrees, the oxide satisfies the formula 0.70<a/(a+b)<0.90, wherein a is the intensity of the maximum X-ray diffraction peak and b is the intensity of a maximum peak among X-ray diffraction peaks in the 20 range of 15 to 22 degrees, and the oxide has a lattice constant of 4.10 to 4.14 ?.
    Type: Application
    Filed: March 5, 2024
    Publication date: October 3, 2024
    Inventors: Kazumasa SAKATSUME, Yoshiyuki MORITA, Yoshiya FUJIWARA, Akihisa TANAKA, Kazuki CHIBA, Takashi HAKARI, Junji AKIMOTO, Kunimitsu KATAOKA
  • Publication number: 20240258560
    Abstract: Disclosed is a nonaqueous electrolyte secondary battery having improved electron conductivity of an electrode and improved input and output characteristics. The nonaqueous electrolyte secondary battery includes a positive electrode containing a lithium-containing transition metal composite oxide as an active material, a negative electrode, and a nonaqueous electrolyte. The negative electrode contains titanium oxide particles that are particles of titanium oxide represented by general formula H2Ti12O25, a binder, and 0.3-5.0 weight percent of single wall carbon nanotubes with respect to the titanium oxide. The titanium oxide particles have a secondary particle size D50 of 1 to 15 ?m and a secondary particle size D90 of 50 ?m or less.
    Type: Application
    Filed: May 18, 2022
    Publication date: August 1, 2024
    Inventors: Keiichiro UENAE, Junji AKIMOTO, Hideaki NAGAI, Seiichi YANO
  • Patent number: 11916227
    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: Grant
    Filed: February 22, 2019
    Date of Patent: February 27, 2024
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Mikito Mamiya, Junji Akimoto
  • Publication number: 20240003052
    Abstract: The lithium composite oxide single crystal has a chemical composition represented by Li7-3x-w-vGaxLa3Zr2-w-vTaWNbvO12 (0.02?x<0.5, 0?W?1.0, 0?V?1.0, and 0.05?W+V?1.0), which belongs to a space group I-43d in a cubic system and has a garnet structure.
    Type: Application
    Filed: November 12, 2021
    Publication date: January 4, 2024
    Inventors: Kunimitsu KATAOKA, Junji AKIMOTO
  • Publication number: 20230378527
    Abstract: Provided is a complex oxide having high density and high lithium ion conductivity and low activation energy. The complex oxide has a chemical composition represented by Li4?xSr2?xLaxZrO6 (0?x?1.0) and belongs to a monoclinic space group P21/n. The relative density of this complex oxide can be made to be 100%. The lithium ion conductivity of this complex oxide can be made to be 6.0×10?4 S/cm or more. This complex oxide is produced by melting at least a part of a raw material having a chemical composition represented by Li(4?x)ySr(2?x)zLaxZrO6 (0?x?1.0, 1<y and 1<z) to form a molten portion and moving the molten portion at a movement speed of 8 mm/h or faster.
    Type: Application
    Filed: August 30, 2021
    Publication date: November 23, 2023
    Inventors: Kunimitsu KATAOKA, Junji AKIMOTO, Sonoko WAKAHARA
  • Publication number: 20230246197
    Abstract: The present invention provides a cathode mixture that can be suitably used in a cathode mixture layer of an all-solid-state lithium-sulfur battery having an excellent charge/discharge capacity and a method of producing the cathode mixture, by maximally utilizing excellent physical properties of sulfur. The present invention relates to a positive electrode mixture for composite all-solid-state lithium-sulfur batteries, the positive electrode mixture containing sulfur or its discharge product (A); phosphorus pentasulfide (B); conductive carbon (C); and lithium halide (D) at a weight ratio of A:B:C:D of 40-60:15-35:5-20:16-30, wherein a peak at 50 ppm in 31P-MAS NMR has a relative intensity of 40% or less.
    Type: Application
    Filed: May 6, 2021
    Publication date: August 3, 2023
    Inventors: Hiroshi NAGATA, Junji AKIMOTO, Takehiko HOSHI, Tadayuki YABE, Yasuo CHIKUSA, Tetsuya OTSUKI
  • Publication number: 20220320578
    Abstract: Provided is a novel solid electrolyte material of high density and high ionic conductivity, and an all-solid-state lithium ion secondary battery that utilizes the solid electrolyte material. The solid electrolyte material has a chemical composition represented by Li7-3xGaxLa3Zr2O12 (0.08?x<0.5), has a relative density of 99% or higher, belongs to space group I-43d, in the cubic system, and has a garnet-type structure. The lithium ion conductivity of the solid electrolyte material is 2.0×10?3 S/cm or higher. The solid electrolyte material has a lattice constant a such that 1.29 nm?a?1.30 nm, and lithium ions occupy the 12a site, the 12b site and two types of 48e site, and gallium occupies the 12a site and the 12b site, in the crystal structure. The all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte. The solid electrolyte is made up of the solid electrolyte material of the present invention.
    Type: Application
    Filed: June 26, 2020
    Publication date: October 6, 2022
    Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Kunimitsu KATAOKA, Junji AKIMOTO, Yuso ISHIDA, Tomoki ARIGA
  • Patent number: 11139504
    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: Grant
    Filed: June 9, 2020
    Date of Patent: October 5, 2021
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Kunimitsu Kataoka, Junji Akimoto
  • 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