Patents by Inventor Tetsuo Sakai

Tetsuo Sakai 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).

  • Patent number: 9350018
    Abstract: A secondary battery includes: a fiber negative electrode having a surface on which a negative electrode active material coating is formed, the coating containing a compound of AaMbXcZd; a fiber positive electrode including a positive electrode active material coating containing nickel hydroxide; an aqueous electrolyte solution; and a separator. The negative electrode coating has an uncoated surface. A is selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba; M is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Ru, Pd, Ag, Ta, W, Pr, Sm, Eu, and Pb; X is selected from the group consisting of B, Al, Si, P, S, Ga, and Ge; Z is selected from the group consisting of O, S, N, F, Cl, Br, and I; and 0?a?6, 1?b?5, 0?c?4, 0<d?12, and 0?a/b?4.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: May 24, 2016
    Assignees: KAWASAKI JUKOGYO KABUSHIKI KAISHA, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Kazuo Tsutsumi, Kazuya Nishimura, Tomoaki Takasaki, Tetsuo Sakai, Jinhan Yao, Takashi Mukai
  • Patent number: 9337476
    Abstract: The present invention provides a process for producing a lithium sulfide-carbon composite, the process comprising placing a mixture of lithium sulfide and a carbon material having a specific surface area of 60 m2/g or more in an electrically-conductive mold in a non-oxidizing atmosphere, and applying a pulsed direct current to the mold while pressurizing the mixture in a non-oxidizing atmosphere, thereby subjecting the lithium sulfide and the carbon material to heating reaction; and a lithium sulfide-carbon composite obtained by this process, the composite having a carbon content of 15 to 70 weight %, and a tap density of 0.4 g/cm3 or more when the carbon content is 30 weight % or more, or a tap density of 0.5 g/cm3 or more when the carbon content is less than 30 weight %.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: May 10, 2016
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Tomonari Takeuchi, Hikari Sakaebe, Tetsuo Sakai, Kuniaki Tatsumi, Hiroshi Senoh, Hiroyuki Kageyama, Mitsuharu Tabuchi
  • Patent number: 9330805
    Abstract: Provided is a novel lithium silicate-based material useful as a positive electrode material for lithium ion secondary battery. The lithium silicate-based compound is represented by Li1.5FeSiO4.25. The lithium silicate-based compound is a compound including: lithium (Li); iron (Fe); silicon (Si); and oxygen (O), and expressed by a composition formula, Li1+2?FeSiO4+??c (?0.25???0.25, 0?c?0.5). The lithium silicate-based compound, of which iron (Fe) is trivalent, exerts a remarkable chemical stability as compared to Li2FeSiO4.
    Type: Grant
    Filed: July 26, 2012
    Date of Patent: May 3, 2016
    Assignees: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Akira Kojima, Toshikatsu Kojima, Mitsuharu Tabuchi, Tetsuo Sakai, Masanori Morishita, Takuhiro Miyuki, Junichi Niwa, Masataka Nakanishi, Yuya Sato, Kazuhito Kawasumi, Masakazu Murase
  • Patent number: 9315390
    Abstract: A production process for lithium-silicate-based compound according to the present invention is characterized in that: a lithium-silicate compound being expressed by Li2SiO3 is reacted with a transition-metal-element-containing substance including at least one member being selected from the group consisting of iron and manganese at 550° C. or less within a molten salt including at least one member being selected from the group consisting of alkali-metal nitrates as well as alkali-metal hydroxides in an atmosphere in the presence of a mixed gas including carbon dioxide and a reducing gas. In accordance with the present invention, it is possible to produce lithium-silicate-based materials, which are useful as a positive-electrode active material for lithium-ion secondary battery, and the like, at low temperatures by means of relatively easy means.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: April 19, 2016
    Assignees: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Toshikatsu Kojima, Takuhiro Miyuki, Tetsuo Sakai, Akira Kojima, Junichi Niwa, Hitotoshi Murase, Kazuhito Kawasumi
  • Publication number: 20160072127
    Abstract: Problem: To provide a lithium secondary battery negative electrode active material consisting of a Sn—Sb based sulfide that delivers a high electrode capacity density, excellent output characteristics, and excellent cycle life characteristics and also provide a method for manufacturing the lithium secondary battery negative electrode active material, said method being capable of easily manufacturing the high performance lithium secondary battery negative electrode active material at low cost without requiring a high-temperature processing step and special facilities as required in a glass melting method. Solution: A method for manufacturing a lithium secondary battery negative electrode active material containing a Sn—Sb based sulfide comprises a step of obtaining a Sn—Sb based sulfide precipitate by adding an alkali metal sulfide to a mixed solution of a tin halide and an antimony halide.
    Type: Application
    Filed: February 26, 2014
    Publication date: March 10, 2016
    Inventors: Takashi MUKAI, Taichi SAKAMOTO, Yuta IKEUCHI, Tetsuo SAKAI, Naoto YAMASHITA, Koichiro IKEDA, Kiichiro YAMAGUCHI
  • Patent number: 9281539
    Abstract: An object of the present invention is to provide a highly efficient electrical storage device that uses a fiber positive electrode and a fiber negative electrode and in which lithium ion is used as an intercalating species, and to provide a method of fabricating the electrical storage device.
    Type: Grant
    Filed: July 13, 2010
    Date of Patent: March 8, 2016
    Assignee: KAWASAKAI JUKOGYO KABUSHIKI KAISHA
    Inventors: Kazuo Tsutsumi, Kazuya Nishimura, Tomoaki Takasaki, Masateru Nakoji, Tetsuo Sakai, Jinhan Yao, Makoto Saito, Takashi Mukai
  • Patent number: 9269954
    Abstract: The present invention is one which provides a production process for lithium-silicate-system compound, the production process being characterized in that: a lithium-silicate compound being expressed by Li2SiO3 is reacted with a substance including at least one member of transition-metal elements that is selected from the group consisting of iron and manganese at 400-650° C. in a molten salt of a carbonate mixture comprising lithium carbonate and at least one member of alkali-metal carbonates that is selected from the group consisting of potassium carbonate, sodium carbonate, rubidium carbonate and cesium carbonate in a mixed-gas atmosphere including carbon dioxide and a reducing gas; and a positive-electrode active material for lithium-ion secondary battery that comprises a lithium-silicate-system compound being obtained by the aforesaid process.
    Type: Grant
    Filed: November 20, 2009
    Date of Patent: February 23, 2016
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventors: Toshikatsu Kojima, Tetsuo Sakai, Takuhiro Miyuki, Yasue Okuyama, Akira Kojima, Junichi Niwa, Hitotoshi Murase
  • Publication number: 20150380729
    Abstract: A lithium-ion secondary battery of the present invention comprises a positive electrode including a positive electrode active material composite formed by compositing a lithium silicate-based material and a carbon material, a negative electrode including a negative electrode active material containing a silicon, and an electrolyte. The lithium-ion secondary battery satisfies 0.8<B/A<1.2, where A is irreversible capacity of the positive electrode and B is irreversible capacity of the negative electrode.
    Type: Application
    Filed: January 8, 2014
    Publication date: December 31, 2015
    Applicants: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Akira KOJIMA, Junichi NIWA, Kazuhito KAWASUMI, Yuta IKEUCHI, Masanori MORISHITA, Toshikatsu KOJIMA, Tetsuo SAKAI
  • Publication number: 20150280220
    Abstract: Problem. Provided is a negative electrode material for a sodium secondary battery and its manufacturing method, and a negative electrode for a sodium secondary battery, and a sodium secondary battery, wherein the negative electrode material can have excellent cycle characteristics while maintaining high discharge capacity. Solution. A negative electrode material for a sodium secondary battery according to the present invention includes sulfide or sulfide composite body containing sulfur and antimony, and as necessary further includes the following component(s) of (i): (i) at least one or more element(s) selected from a group consisting of Sn, As, Bi, Ge, Ga, Pb, and C, wherein when a component(s) of (i) is included, the ratio of each of the above described components is sulfur: 10 to 70 mol %, antimony: 10 to 70 mol %, and (i): 3 to 60 mol %.
    Type: Application
    Filed: November 1, 2012
    Publication date: October 1, 2015
    Inventors: Takashi MUKAI, Taichi SAKAMOTO, Yuta IKEUCHI, Tetsuo SAKAI, Kunihiko TANI, Naoto YAMASHITA, Koichiro IKEDA, Kiichiro YAMAGUCHI
  • Publication number: 20150280237
    Abstract: This binder for use in a positive electrode for a lithium ion secondary battery contains a copolymer of both vinyl alcohol and an alkali-metal-neutralized ethylenically unsaturated carboxylic acid.
    Type: Application
    Filed: October 1, 2013
    Publication date: October 1, 2015
    Inventors: Takashi Mukai, Masanori Morishita, Tetsuo Sakai, Yuji Kinpara, Junichi Fujishige, Nobutaka Fujimoto, Shuichi Karashima
  • Patent number: 9082525
    Abstract: A lithium silicate-based compound according to the present invention is expressed by a general formula, Li(2?a+b)AaMn(1?x?y)CoxMySiO(4+?)Cl? (In the formula: “A” is at least one element selected from the group consisting of Na, K, Rb and Cs; “M” is at least one member selected from the group consisting of Mg, Ca, Al, Ni, Fe, Nb, Ti, Cr, Cu, Zn, Zr, V, Mo and W; and the respective subscripts appear to be as follows: 0?“a”<0.2; 0?“b”<1; 0<“x”<1; 0?“y”?0.5; ?0.25?“?”?1.25; and 0?“?”?0.05). The lithium silicate-based compound is used as a positive-electrode active material for secondary battery whose discharge average voltage is higher, and which is able to sorb and desorb lithium ions.
    Type: Grant
    Filed: October 12, 2012
    Date of Patent: July 14, 2015
    Assignees: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Akira Kojima, Toshikatsu Kojima, Mitsuharu Tabuchi, Tetsuo Sakai, Takuhiro Miyuki, Junichi Niwa, Kazuhito Kawasumi, Masakazu Murase
  • Patent number: 9070941
    Abstract: [Object] The object is to provide a negative electrode material for a lithium secondary battery, wherein a sulfide-based negative electrode with water-resistant properties can exert excellent cycle characteristics and high output performance while maintaining a high discharge capacity and there is no precipitation of lithium dendrites during charge at low temperature. [Means for Solving Problems] A negative electrode material for a lithium secondary battery comprising sulfur and sulfide glass including the following components (i) and (ii): (i) at least one or more elements selected from a group consisting of Sb, As, Bi, Ge, Si, Cu, Zn, Pd, In and Zr; and (ii) at least one or more elements selected from a group consisting of Se, Te, Ga, Sn, Pb, Cd, Al, Fe, Mg, Ca, Co, Ag, Sr, P and Ba, wherein the ratio of the above components is sulfur: 40-80 mol %, (i): 1-50 mol % and (ii): 1-50 mol %, respectively.
    Type: Grant
    Filed: December 9, 2011
    Date of Patent: June 30, 2015
    Assignees: National Institute of Advanced Industrial Science and Technology, Isuzu Glass Company, Ltd.
    Inventors: Takashi Mukai, Taichi Sakamoto, Tetsuo Sakai, Kunihiko Tani, Naoto Yamashita, Koichiro Ikeda
  • Patent number: 9065139
    Abstract: Provided is a method for mass manufacturing, at low cost, of a fiber positive electrode for a lithium secondary battery, which has excellent charge/discharge cycle characteristics, and which is capable of charging/discharging with high current density, and a main active material of which is a lithium-doped transition metal oxide. The method includes the steps of: (a) forming a tubular coating of either a transition metal oxide or a transition metal hydroxide on a carbon fiber current collector; and (b) performing, in a lithium ion containing solution in a sealed system under presence of an oxidant or a reductant, heat treatment at 100 to 250° C. on the carbon fiber current collector, on which the tubular coating of either the transition metal oxide or the transition metal hydroxide is formed, to obtain a coating of a lithium-doped transition metal oxide on the carbon fiber current collector.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: June 23, 2015
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, KAWASAKI JUKOGYO KABUSHIKI KAISHA
    Inventors: Tetsuo Sakai, Jinhan Yao, Takashi Mukai, Tomoaki Takasaki, Kazuo Tsutsumi, Kazuya Nishimura
  • Publication number: 20150171418
    Abstract: A negative electrode active material for an electricity storage device comprises at least SnO as a composition thereof. When a binding energy value of an electron on a Sn 3d5/2 orbital of a Sn atom in the negative electrode active material for an electricity storage device is defined as Pl and a binding energy value of an electron on a Sn 3d5/2 orbital of a metal Sn is defined as Pm, (Pl?Pm) is 0.01 to 3.5 eV.
    Type: Application
    Filed: February 27, 2015
    Publication date: June 18, 2015
    Inventors: Hideo YAMAUCHI, Tomohiro NAGAKANE, Akihiko SAKAMOTO, Tetsuo SAKAI, Meijing ZOU
  • Publication number: 20150118557
    Abstract: Provided is a hydrogen storage alloy which is characterized in that two or more crystal phases having different crystal structures are layered in a c-axis direction of the crystal structures. The hydrogen storage alloy is further characterized in that a difference between a maximum value and a minimum value of a lattice constant a in the crystal structures of the laminated two or more crystal phases is 0.03 ? or less.
    Type: Application
    Filed: January 6, 2015
    Publication date: April 30, 2015
    Applicants: GS Yuasa International Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Tadashi KAKEYA, Manabu KANEMOTO, Minoru KUZUHARA, Tetsuya OZAKI, Masaharu WATADA, Tetsuo SAKAI
  • Patent number: 9017870
    Abstract: Provided is a negative electrode material for an electricity storage device, comprises, a negative electrode active material comprising a compound containing at least SnO and P2O5, and a binder comprising a thermosetting resin. Also provided is a negative electrode for an electricity storage device, comprising a current collector having a surface coated with the negative electrode material for an electricity storage device. Further provided is a method of producing the negative electrode for an electricity storage device, the method comprising the steps of: coating the surface of the current collector with the negative electrode material for an electricity storage device; and carrying out heat treatment of the current collector at 150 to 400° C. under reduced pressure.
    Type: Grant
    Filed: November 19, 2010
    Date of Patent: April 28, 2015
    Assignees: Nippon Electric Glass Co., Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Hideo Yamauchi, Tomohiro Nagakane, Akihiko Sakamoto, Tetsuo Sakai, Meijing Zou
  • Patent number: 8968932
    Abstract: A compound having a high reduction resistance and being capable of sufficiently performing a function as an electronic conductive additive when added to a positive electrode active material as an electronic conductive additive is provided. In a method for producing a cobalt cerium compound including a step of depositing a hydroxide containing cobalt and cerium in an aqueous solution containing cobalt ions and cerium ions by changing the pH of the aqueous solution and thereafter performing a treatment of oxidizing the hydroxide, the ratio of the cerium ions contained in the aqueous solution containing the cobalt ions and the cerium ions is set to be more than 5% by atom and 70% by atom or less with respect to the sum of the cobalt ions and the cerium ions before the hydroxide is deposited.
    Type: Grant
    Filed: July 16, 2010
    Date of Patent: March 3, 2015
    Assignees: GS Yuasa International Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Masanori Morishita, Tadashi Kakeya, Seijiro Ochiai, Aki Nakashima, Yoshiteru Kawabe, Tetsuo Sakai
  • Patent number: 8940436
    Abstract: Provided is a sulfur-modified polyacrylonitrile manufacturing method that is characterized in that a starting base powder that comprises sulfur powder and polyacrylonitrile powder is mixed and the mixture is heated in a non-oxidizing environment while outflow of sulfur vapor is prevented. Also provided are a cathode for lithium batteries that uses, as the active substance, the sulfur-modified polyacrylonitrile manufactured with the method, and a lithium secondary battery that includes the cathode as a component element. This enables the practical use of an inexpensive sulfur-based material as the cathode material for lithium secondary batteries, and in particular, a sulfur-based cathode material that enables higher output and has excellent cycle life characteristics, as well as other characteristics, and secondary lithium batteries using the same can be obtained.
    Type: Grant
    Filed: October 15, 2009
    Date of Patent: January 27, 2015
    Assignees: National Institute of Advanced Industrial Science and Technology, Kabushiki Kaisha Toyota Jidoshokki
    Inventors: Takuhiro Miyuki, Tetsuo Sakai, Junichi Niwa, Hitotoshi Murase
  • Publication number: 20150017534
    Abstract: Disclosed is a resin composition for positive electrodes of lithium ion cells, which imparts strong adhesiveness and electrolyte injectability and shows good discharge and charge characteristics and input-output characteristics with smaller amount of a binder. The resin composition for positive electrodes of lithium ion cells is a resin composition for positive electrodes of lithium ion cells, which comprises a polyimide precursor whose average thermal linear expansion coefficient in the range of 20° C. to 200° C. after being imidized is 3 to 50 ppm, and/or a polyimide whose average thermal linear expansion coefficient in the range of 20° C. to 200° C. is 3 to 50 ppm, and a positive electrode active compound, wherein the positive electrode active compound is one obtained by coating the surface of a composite oxide containing lithium with a lithium ion conductive material.
    Type: Application
    Filed: January 30, 2013
    Publication date: January 15, 2015
    Inventors: Takuhiro Miyuki, Yasue Okuyama, Tetsuo Sakai, Tomoyuki Yuba, Natsuko Chayama, Masao Tomikawa
  • Publication number: 20140332718
    Abstract: A lithium silicate-based compound according to the present invention is expressed by a general formula, Li(2?a+b)AaMn(1?x?y)CoxMySiO(4+?)Cl? (In the formula: “A” is at least one element selected from the group consisting of Na, K, Rb and Cs; “M” is at least one member selected from the group consisting of Mg, Ca, Al, Ni, Fe, Nb, Ti, Cr, Cu, Zn, Zr, V, Mo and W; and the respective subscripts appear to be as follows: 0?“a”<0.2; 0?“b”<1; 0<“x”<1; 0?“y”?0.5; ?0.25?“?”?1.25; and 0?“?”?0.05). The lithium silicate-based compound is used as a positive-electrode active material for secondary battery whose discharge average voltage is higher, and which is able to sorb and desorb lithium ions.
    Type: Application
    Filed: October 12, 2012
    Publication date: November 13, 2014
    Applicants: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Akira Kojima, Toshikatsu Kojima, Mitsuharu Tabuchi, Tetsuo Sakai, Takuhiro Miyuki, Junichi Niwa, Kazuhito Kawasumi, Masakazu Murase