Patents by Inventor Ayuko Kitajou

Ayuko Kitajou 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: 20240154117
    Abstract: Provided are a sodium titanium phosphate salt and, additionally, at least one of a negative electrode active material that gives a sodium secondary battery having superior power characteristics as compared to conventional aqueous sodium secondary batteries and a sodium secondary battery including such a negative electrode active material. In particular, provided is a negative electrode active material that gives an aqueous sodium secondary battery having superior power characteristics as compared to conventional aqueous sodium secondary batteries including NASICON type NaTi2(PO4)3 as a negative electrode active material. A sodium titanium phosphate salt represented by the general formula Na1+xTi2(PO4)3 (where 0?x?2) includes a surface layer containing Na5Ti(PO4)3.
    Type: Application
    Filed: March 2, 2022
    Publication date: May 9, 2024
    Applicants: YAMAGUCHI UNIVERSITY, TOSOH CORPORATION
    Inventors: Ayuko KITAJOU, Maho YAMASHITA, Masaki OKADA, Wataru KOBAYASHI, Toshiya TAKAHARA
  • Patent number: 11355752
    Abstract: A positive electrode active substance for the non-aqueous secondary battery is provided. The positive electrode active substance includes a metal or a metal compound including the metal element M1 exhibiting a conversion reaction and/or a reverse conversion reaction, and an amorphous metal oxide of the metal element M2. M2 includes at least one metal element selected from the group consisting of V, Cr, Mo, Mn, Ti, and Ni.
    Type: Grant
    Filed: December 20, 2019
    Date of Patent: June 7, 2022
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Shigeto Okada, Ayuko Kitajou
  • Publication number: 20200243857
    Abstract: A positive electrode active substance for the non-aqueous secondary battery is provided. The positive electrode active substance includes a metal or a metal compound including the metal element M1 exhibiting a conversion reaction and/or a reverse conversion reaction, and an amorphous metal oxide of the metal element M2. M2 includes at least one metal element selected from the group consisting of V, Cr, Mo, Mn, Ti, and Ni.
    Type: Application
    Filed: December 20, 2019
    Publication date: July 30, 2020
    Inventors: Shigeto OKADA, Ayuko KITAJOU
  • Patent number: 9780369
    Abstract: The present invention is to provide a cathode active material configured to increase, when used in a lithium battery, the discharge capacity of the lithium battery higher than conventional lithium batteries, and a lithium battery including the cathode active material. Presented is a cathode active material for lithium batteries, wherein the cathode active material is represented by the following composition formula (1) and has a rock salt type crystal structure including formula (1): Li2Ni1-x-yCoxMnyTiO4 wherein x and y are real numbers that satisfy x>0, y>0 and x+y<1.
    Type: Grant
    Filed: November 12, 2013
    Date of Patent: October 3, 2017
    Assignees: KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Shigeto Okada, Ayuko Kitajou, Ryuichi Tsuji, Jun Yoshida, Shinji Nakanishi
  • Patent number: 9312538
    Abstract: Provided is a technology for producing a positive electrode active substance mainly composed of FeOF having a sufficient charge-discharge capacity, in the short-time and easy manner. Also provided is a positive electrode active substance mainly composed of FeOF. The method for producing the positive electrode active substance mainly composed of FeOF comprises the steps of admixing iron oxide Fe2O3 and iron fluoride FeF3 both in solid states, and melt-quenching the mixture in an atmosphere of inert gas. The positive electrode active substance mainly composed of FeOF is composed of not less than 50% by weight of FeOF with a remainder being iron fluoride FeF3 and/or iron oxide Fe2O3.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: April 12, 2016
    Assignee: Kyushu University, National University Corporation
    Inventors: Shigeto Okada, Ayuko Kitajou, Hideyuki Komatsu, Irina D. Gocheva, Kuniko Chihara, Junichi Yamaki
  • Publication number: 20150295243
    Abstract: The problem of the present invention is to provide a cathode active material which performs favorable discharge capacity. The present invention solves the problem by providing a cathode active material comprising a crystal phase of an inverse-spinel structure represented by LiM1?xFexVO4 (M is Co or Ni, and x satisfies 0<x<1).
    Type: Application
    Filed: November 12, 2013
    Publication date: October 15, 2015
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION
    Inventors: Shigeto Okada, Ayuko Kitajou, Jun Yoshida, Shinji Nakanishi
  • Publication number: 20150295237
    Abstract: The present invention is to provide a cathode active material configured to increase, when used in a lithium battery, the discharge capacity of the lithium battery higher than conventional lithium batteries, and a lithium battery including the cathode active material. Presented is a cathode active material for lithium batteries, wherein the cathode active material is represented by the following composition formula (1) and has a rock salt type crystal structure including formula (1): Li2Ni1-x-yCoxMnyTiO4 wherein x and y are real numbers that satisfy x>0, y>0 and x+y<1.
    Type: Application
    Filed: November 12, 2013
    Publication date: October 15, 2015
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION
    Inventors: Shigeto Okada, Ayuko Kitajou, Ryuichi Tsuji, Jun Yoshida, Shinji Nakanishi
  • Publication number: 20140291573
    Abstract: Provided is a technology for producing a positive electrode active substance mainly composed of FeOF having a sufficient charge-discharge capacity, in the short-time and easy manner. Also provided is a positive electrode active substance mainly composed of FeOF. The method for producing the positive electrode active substance mainly composed of FeOF comprises the steps of admixing iron oxide Fe2O3 and iron fluoride FeF3 both in solid states, and melt-quenching the mixture in an atmosphere of inert gas. The positive electrode active substance mainly composed of FeOF is composed of not less than 50% by weight of FeOF with a remainder being iron fluoride FeF3 and/or iron oxide Fe2O3.
    Type: Application
    Filed: June 22, 2012
    Publication date: October 2, 2014
    Applicant: KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION
    Inventors: Shigeto Okada, Ayuko Kitajou, Hideyuki Komatsu, Irina D. Gocheva, Kuniko Chihara, Junichi Yamaki