Patents by Inventor Shigeto Okada

Shigeto Okada 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: 20230049879
    Abstract: There are provided an aqueous electrolyte solution having an extended potential window, in particular, an aqueous electrolyte solution whose potential window is further wider than those exhibited by conventional concentrated aqueous electrolyte solutions, and an aqueous electrolyte solution in which the cycle characteristics can be improved. A non-aqueous electrolyte solution capable of achieving a higher energy density is provided, the non-aqueous electrolyte solution containing easily available and inexpensive materials and having further improved characteristics. One aqueous electrolyte solution of the present embodiment contains a salt of at least one selected from the group consisting of sodium, magnesium, potassium and lithium, and a chaotropic additive. One other non-aqueous electrolyte solution of the present embodiment contains a salt of at least one selected from the group consisting of sodium, magnesium, potassium and lithium, and a chaotropic additive.
    Type: Application
    Filed: November 2, 2020
    Publication date: February 16, 2023
    Applicants: KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION, TOSOH CORPORATION
    Inventors: Shigeto OKADA, Ryo SAKAMOTO, Masato ITO, Kotaro USHIJIMA, Toshiya TAKAHARA, Wataru KOBAYASHI, Masaki OKADA
  • Publication number: 20220223924
    Abstract: To provide an aqueous sodium ion secondary battery which can achieve a high electrochemical capacity as compared with a known sodium ion secondary battery having an aqueous electrolytic solution. An aqueous sodium ion secondary battery includes a cathode, an anode, an electrolytic solution and a separator, wherein the cathode has at least a cathode active material containing at least a sodium transition metal polyanion represented by the formula Na3-xMPO4CO3 (M is at least one member selected from the group consisting of Fe, Mn, Ni and Co, and x is 0 or more and 2 or less), and the electrolytic solution is an aqueous electrolytic solution.
    Type: Application
    Filed: May 27, 2020
    Publication date: July 14, 2022
    Applicants: KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION, TOSOH CORPORATION
    Inventors: Shigeto OKADA, Baowei XIE, Toshiya TAKAHARA, Wataru KOBAYASHI, Masaki OKADA
  • 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
  • Patent number: 9209486
    Abstract: An all-solid-state cell contains a combination of an electrode active material and a solid electrolyte, and has a plate-shaped fired solid electrolyte body of a ceramic containing a solid electrolyte, a first electrode layer (e.g. a positive electrode) integrally formed on one surface of the fired solid electrolyte body by mixing and firing an electrode active material and a solid electrolyte, and a second electrode layer (e.g. a negative electrode) integrally formed on the other surface of the fired solid electrolyte body by mixing and firing an electrode active material and a solid electrolyte. The solid electrolyte materials added to the first electrode layer and the second electrode layer comprise an amorphous polyanion compound.
    Type: Grant
    Filed: March 19, 2014
    Date of Patent: December 8, 2015
    Assignees: Kyushu University, NGK Insulators, Ltd.
    Inventors: Shigeto Okada, Eiji Kobayashi, Kazuhiro Yamamoto, Toshihiro Yoshida, Yosuke Sato
  • Patent number: 9209484
    Abstract: An all-solid-state cell has a fired solid electrolyte body, a first electrode layer integrally formed on one surface of the fired solid electrolyte body by mixing and firing an electrode active material and a solid electrolyte, and a second electrode layer integrally formed on the other surface of the fired solid electrolyte body by mixing and firing an electrode active material and a solid electrolyte. The first and the second electrode layers are formed by mixing and firing the electrode active material and the amorphous solid electrolyte, which satisfy the relation Ty>Tz (wherein Ty is a temperature at which the capacity of the electrode active material is lowered by reaction between the electrode active material and the solid electrolyte material, and Tz is a temperature at which the solid electrolyte material is shrunk by firing).
    Type: Grant
    Filed: March 24, 2014
    Date of Patent: December 8, 2015
    Assignees: Kyushu University, NGK Insulators, Ltd.
    Inventors: Shigeto Okada, Eiji Kobayashi, Kazuhiro Yamamoto, Toshihiro Yoshida, Yosuke Sato
  • 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: 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
  • Patent number: 8974963
    Abstract: A lithium secondary battery includes: a positive electrode that contains a positive electrode active material; a negative electrode; and a nonaqueous electrolyte. The positive electrode active material is amorphous and is expressed by LixA[PaM1-a]yOz where, in the formula, A is Mn or Ni; M is a glass former element having an electronegativity lower than P; and x, y, a and z respectively satisfy 1<x?2.5, 0<y?3, 0?a<1 and z=(x+(valence of A)+(valence of P)×a×y+(valence of M)×(1?a)×y)/2.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: March 10, 2015
    Assignees: Toyota Jidosha Kabushiki Kaisha, Kyushu University, National University Corporation
    Inventors: Motoshi Isono, Shigeto Okada, Jun-ichi Yamaki
  • Patent number: 8865349
    Abstract: The present invention provides a positive electrode active material that has rate characteristics suitable for nonaqueous electrolyte batteries and particularly nonaqueous electrolyte secondary batteries, a method by which this positive electrode active material can be easily mass produced, and a high-performance nonaqueous electrolyte battery that has a positive electrode active material obtained by this method. The present invention relates to a method of producing a positive electrode active material, the method comprising a step of mixing a carbon source with lithium manganese phosphate LiMnPO4 or a compound LiMn1-xMxPO4 (where, 0?x<1 and M is at least one metal element selected from the group consisting of Co, Ni, Fe, Zn, Cu, Ti, Sn, Zr, V, and Al) containing lithium manganese phosphate LiMnPO4 as a solid solution composition, and heat treating the obtained mixture under an inert gas atmosphere.
    Type: Grant
    Filed: September 20, 2006
    Date of Patent: October 21, 2014
    Assignees: Kanto Denka Kogyo Co., Ltd., Kyushu University, National University Corporation
    Inventors: Shigeto Okada, Tomoyuki Shiratsuchi, Tomoko Iwanaga, Jun-ichi Yamaki, Shinji Iizuka, Osamu Omae, Kumiko Sueto, Takeshi Shimada
  • 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
  • Publication number: 20140205890
    Abstract: An all-solid-state cell contains a combination of an electrode active material and a solid electrolyte, and has a plate-shaped fired solid electrolyte body of a ceramic containing a solid electrolyte, a first electrode layer (e.g. a positive electrode) integrally formed on one surface of the fired solid electrolyte body by mixing and firing an electrode active material and a solid electrolyte, and a second electrode layer (e.g. a negative electrode) integrally formed on the other surface of the fired solid electrolyte body by mixing and firing an electrode active material and a solid electrolyte. The solid electrolyte materials added to the first electrode layer and the second electrode layer comprise an amorphous polyanion compound.
    Type: Application
    Filed: March 19, 2014
    Publication date: July 24, 2014
    Applicants: NGK Insulators, Ltd., Kyushu University
    Inventors: Shigeto OKADA, Eiji KOBAYASHI, Kazuhiro YAMAMOTO, Toshihiro YOSHIDA, Yosuke SATO
  • Publication number: 20140205891
    Abstract: An all-solid-state cell has a fired solid electrolyte body, a first electrode layer integrally formed on one surface of the fired solid electrolyte body by mixing and firing an electrode active material and a solid electrolyte, and a second electrode layer integrally formed on the other surface of the fired solid electrolyte body by mixing and firing an electrode active material and a solid electrolyte. The first and the second electrode layers are formed by mixing and firing the electrode active material and the amorphous solid electrolyte, which satisfy the relation Ty>Tz (wherein Ty is a temperature at which the capacity of the electrode active material is lowered by reaction between the electrode active material and the solid electrolyte material, and Tz is a temperature at which the solid electrolyte material is shrunk by firing).
    Type: Application
    Filed: March 24, 2014
    Publication date: July 24, 2014
    Applicants: NGK Insulators, Ltd., Kyushu University
    Inventors: Shigeto OKADA, Eiji KOBAYASHI, Kazuhiro YAMAMOTO, Toshihiro YOSHIDA, Yosuke SATO
  • Patent number: 8709655
    Abstract: Disclosed is a positive electrode active material for nonaqueous electrolyte secondary batteries which contains a complex oxide mainly containing sodium, nickel and a tetravalent metal while having a hexagonal structure. This positive electrode active material enables to obtain a nonaqueous electrolyte secondary battery with high operating voltage. The complex oxide is preferably expressed as Na[Na(1/3-2x/3)Ni(x-y)M(2/3-x/3-y)A2y]O2 (wherein M represents one or more tetravalent metals, A represents one or more trivalent metals, 0<x?0.5, 0?y<1/6, and x>y).
    Type: Grant
    Filed: November 24, 2005
    Date of Patent: April 29, 2014
    Assignees: Sumitomo Chemical Company, Limited, Kyushu University, National University Corporation
    Inventors: Shigeto Okada, Jun-ichi Yamaki, Yusuke Takahashi, Kenji Nakane
  • Patent number: 8703334
    Abstract: Electrode active material that is used together with an electrolyte solution having an electrolyte decomposition potential Ve is represented by the general expression LixFeMyO2 and is amorphous. In the expression, x and y are values which independently satisfy 1<x?2.5 and O<y?3, respectively, and z=(x+(valence of Fe)+(valence of M)×y)/2 to satisfy stoichiometry, and M represents one or two or more types of glass former element. The average electronegativity of M is less than (Ve+6.74/5.41.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: April 22, 2014
    Assignees: Kyushu University, National University Corporation, Toyota Jidosha Kabushiki Kaisha
    Inventors: Shigeto Okada, Jun-ichi Yamaki, Tetsuya Waseda, Motoshi Isono
  • Patent number: 8454925
    Abstract: In a non-aqueous electrolyte secondary battery, in order to adjust a cathode active material in which guest cation such as Na and Li is included, alkaline metal fluoride which is expressed by a general formula AF and transition metal fluoride which is expressed by a formula M? F2 are subjected to a mechanical milling process to produce metal fluoride compound AM? F3. The mechanical milling process desirably uses a planetary ball mill.
    Type: Grant
    Filed: November 16, 2007
    Date of Patent: June 4, 2013
    Assignees: Mitsubishi Heavy Industries, Ltd., Kyushu University, National University Corporation
    Inventors: Shigeto Okada, Manabu Nishijima, Takayuki Doi, Jun-ichi Yamaki, Irina D. Gocheva, Toshiyasu Kiyabu
  • Publication number: 20120183857
    Abstract: A lithium secondary battery includes: a positive electrode that contains a positive electrode active material; a negative electrode; and a nonaqueous electrolyte. The positive electrode active material is amorphous and is expressed by LixA[PaM1 -a]yOz where, in the formula, A is Mn or Ni; M is a glass former element having an electronegativity lower than P; and x, y, a and z respectively satisfy 1<x?2.5, 0<y?3, 0?a<1 and z=(x+(valence of A)+(valence of P)×axy+(valence of M)×(1-a)xy)/2.
    Type: Application
    Filed: September 30, 2010
    Publication date: July 19, 2012
    Inventors: Motoshi Isono, Shigeto Okada, Jun-ichi Yamaki
  • Patent number: 8197972
    Abstract: A first paste for a first electrode layer and a second paste for a second electrode layer are printed on a fired solid electrolyte by screen printing, etc. to form electrode patterns for forming the first electrode layer and the second electrode layer. The first and second pastes can be prepared by dissolving a binder in an organic solvent, adding an appropriate amount of the obtained solution to powders of an electrode active substance material and a solid electrolyte material, and kneading the resultant mixture. The first and second pastes are applied to the fired solid electrolyte to form a cell precursor, the cell precursor is placed in a hot press mold subjected to a thermal treatment while pressing from above by a punch, whereby the first and second electrode layer are formed from the first and second pastes.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: June 12, 2012
    Assignees: Kyushu University, NGK Insulators, Ltd.
    Inventors: Shigeto Okada, Eiji Kobayashi, Kazuhiro Yamamoto, Toshihiro Yoshida