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).
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Publication number: 20230049879Abstract: 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: ApplicationFiled: November 2, 2020Publication date: February 16, 2023Applicants: KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION, TOSOH CORPORATIONInventors: Shigeto OKADA, Ryo SAKAMOTO, Masato ITO, Kotaro USHIJIMA, Toshiya TAKAHARA, Wataru KOBAYASHI, Masaki OKADA
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Publication number: 20220223924Abstract: 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: ApplicationFiled: May 27, 2020Publication date: July 14, 2022Applicants: KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION, TOSOH CORPORATIONInventors: Shigeto OKADA, Baowei XIE, Toshiya TAKAHARA, Wataru KOBAYASHI, Masaki OKADA
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Patent number: 11355752Abstract: 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: GrantFiled: December 20, 2019Date of Patent: June 7, 2022Assignee: Murata Manufacturing Co., Ltd.Inventors: Shigeto Okada, Ayuko Kitajou
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Publication number: 20200243857Abstract: 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: ApplicationFiled: December 20, 2019Publication date: July 30, 2020Inventors: Shigeto OKADA, Ayuko KITAJOU
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Patent number: 9780369Abstract: 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: GrantFiled: November 12, 2013Date of Patent: October 3, 2017Assignees: KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Shigeto Okada, Ayuko Kitajou, Ryuichi Tsuji, Jun Yoshida, Shinji Nakanishi
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Patent number: 9312538Abstract: 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: GrantFiled: June 22, 2012Date of Patent: April 12, 2016Assignee: Kyushu University, National University CorporationInventors: Shigeto Okada, Ayuko Kitajou, Hideyuki Komatsu, Irina D. Gocheva, Kuniko Chihara, Junichi Yamaki
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Patent number: 9209486Abstract: 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: GrantFiled: March 19, 2014Date of Patent: December 8, 2015Assignees: Kyushu University, NGK Insulators, Ltd.Inventors: Shigeto Okada, Eiji Kobayashi, Kazuhiro Yamamoto, Toshihiro Yoshida, Yosuke Sato
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Patent number: 9209484Abstract: 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: GrantFiled: March 24, 2014Date of Patent: December 8, 2015Assignees: Kyushu University, NGK Insulators, Ltd.Inventors: Shigeto Okada, Eiji Kobayashi, Kazuhiro Yamamoto, Toshihiro Yoshida, Yosuke Sato
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Publication number: 20150295237Abstract: 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: ApplicationFiled: November 12, 2013Publication date: October 15, 2015Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATIONInventors: Shigeto Okada, Ayuko Kitajou, Ryuichi Tsuji, Jun Yoshida, Shinji Nakanishi
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Publication number: 20150295243Abstract: 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: ApplicationFiled: November 12, 2013Publication date: October 15, 2015Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATIONInventors: Shigeto Okada, Ayuko Kitajou, Jun Yoshida, Shinji Nakanishi
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Patent number: 8974963Abstract: 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: GrantFiled: September 30, 2010Date of Patent: March 10, 2015Assignees: Toyota Jidosha Kabushiki Kaisha, Kyushu University, National University CorporationInventors: Motoshi Isono, Shigeto Okada, Jun-ichi Yamaki
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Patent number: 8865349Abstract: 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: GrantFiled: September 20, 2006Date of Patent: October 21, 2014Assignees: Kanto Denka Kogyo Co., Ltd., Kyushu University, National University CorporationInventors: Shigeto Okada, Tomoyuki Shiratsuchi, Tomoko Iwanaga, Jun-ichi Yamaki, Shinji Iizuka, Osamu Omae, Kumiko Sueto, Takeshi Shimada
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Publication number: 20140291573Abstract: 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: ApplicationFiled: June 22, 2012Publication date: October 2, 2014Applicant: KYUSHU UNIVERSITY, NATIONAL UNIVERSITY CORPORATIONInventors: Shigeto Okada, Ayuko Kitajou, Hideyuki Komatsu, Irina D. Gocheva, Kuniko Chihara, Junichi Yamaki
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Publication number: 20140205890Abstract: 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: ApplicationFiled: March 19, 2014Publication date: July 24, 2014Applicants: NGK Insulators, Ltd., Kyushu UniversityInventors: Shigeto OKADA, Eiji KOBAYASHI, Kazuhiro YAMAMOTO, Toshihiro YOSHIDA, Yosuke SATO
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Publication number: 20140205891Abstract: 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: ApplicationFiled: March 24, 2014Publication date: July 24, 2014Applicants: NGK Insulators, Ltd., Kyushu UniversityInventors: Shigeto OKADA, Eiji KOBAYASHI, Kazuhiro YAMAMOTO, Toshihiro YOSHIDA, Yosuke SATO
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Patent number: 8709655Abstract: 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: GrantFiled: November 24, 2005Date of Patent: April 29, 2014Assignees: Sumitomo Chemical Company, Limited, Kyushu University, National University CorporationInventors: Shigeto Okada, Jun-ichi Yamaki, Yusuke Takahashi, Kenji Nakane
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Patent number: 8703334Abstract: 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: GrantFiled: March 28, 2008Date of Patent: April 22, 2014Assignees: Kyushu University, National University Corporation, Toyota Jidosha Kabushiki KaishaInventors: Shigeto Okada, Jun-ichi Yamaki, Tetsuya Waseda, Motoshi Isono
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Patent number: 8454925Abstract: 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: GrantFiled: November 16, 2007Date of Patent: June 4, 2013Assignees: Mitsubishi Heavy Industries, Ltd., Kyushu University, National University CorporationInventors: Shigeto Okada, Manabu Nishijima, Takayuki Doi, Jun-ichi Yamaki, Irina D. Gocheva, Toshiyasu Kiyabu
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Publication number: 20120183857Abstract: 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: ApplicationFiled: September 30, 2010Publication date: July 19, 2012Inventors: Motoshi Isono, Shigeto Okada, Jun-ichi Yamaki
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Patent number: 8197972Abstract: 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: GrantFiled: February 18, 2009Date of Patent: June 12, 2012Assignees: Kyushu University, NGK Insulators, Ltd.Inventors: Shigeto Okada, Eiji Kobayashi, Kazuhiro Yamamoto, Toshihiro Yoshida