Patents by Inventor Toyotaka Yuasa

Toyotaka Yuasa 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: 20070259266
    Abstract: The object of the invention is to provide positive electrode material in which a discharge rate characteristic and battery capacity are hardly deteriorated in the environment of low temperature of ?30° C., its manufacturing method and a lithium secondary battery using the positive electrode material. The invention is characterized by the positive electrode material in which plural primary particles are flocculated and a secondary particle is formed, and the touch length of the primary particles is equivalent to 10 to 70% of the length of the whole periphery on the section of the touched primary particles.
    Type: Application
    Filed: May 8, 2007
    Publication date: November 8, 2007
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Genei Nakajima
  • Publication number: 20070212602
    Abstract: The object of the invention is to provide positive electrode material in which a discharge rate characteristic and battery capacity are hardly deteriorated in the environment of low temperature of ?30° C., its manufacturing method and a lithium secondary battery using the positive electrode material. The invention is characterized by the positive electrode material in which plural primary particles are flocculated and a secondary particle is formed, and the touch length of the primary particles is equivalent to 10 to 70% of the length of the whole periphery on the section of the touched primary particles.
    Type: Application
    Filed: May 8, 2007
    Publication date: September 13, 2007
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Genei Nakajima
  • Publication number: 20070160906
    Abstract: The present invention provides a lithium secondary battery small in the volume variation caused by charge-discharge and excellent in cycle performance. The lithium secondary battery includes a cathode capable of storing and releasing lithium and an anode capable of storing and releasing lithium, the cathode including a lithium-nickel-manganese-cobalt compound oxide having a layered crystal structure and a lithium-manganese compound oxide having a layered crystal structure distributed in the lithium-nickel-manganese-cobalt compound oxide.
    Type: Application
    Filed: January 5, 2007
    Publication date: July 12, 2007
    Inventors: Tatsuya TOOYAMA, Toyotaka Yuasa, Sai Ogawa
  • Publication number: 20060141361
    Abstract: A positive electrode material for lithium secondary battery having high electron conductivity even at very low temperatures, a production method thereof, and a lithium secondary battery with the use of the positive electrode material are provided. The characteristic feature of this positive electrode material for lithium secondary battery is that a positive electrode active material having secondary particles formed of primary particles made of lithium complex oxides and ultrathin carbon fibers having lengths equal to or smaller than the diameters of the secondary particles of the positive electrode active material are composited.
    Type: Application
    Filed: December 8, 2005
    Publication date: June 29, 2006
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Sai Ogawa
  • Publication number: 20060046142
    Abstract: A lithium secondary battery that is highly safe and has long life. The battery, which is a nonaqueous lithium secondary battery, utilizes a cathode active material comprising a complex oxide material having a layered structure containing at least Li and Ni and being represented by the chemical formula LixNia(MnyM1-y)b(COzM?1-z)cO2(0<x<1.2, 0<y<1, 0<z<1, a+b+c=1, 9b?5a+2.7, 0<a<1, 0<b<1, 0<c<1, M: quadrivalent element other than Mn, and M?: trivalent element other than Co).
    Type: Application
    Filed: August 26, 2005
    Publication date: March 2, 2006
    Inventors: Masahiro Kasai, Toyotaka Yuasa
  • Publication number: 20050142442
    Abstract: A positive electrode material for a nonaqueous lithium secondary battery and a lithium secondary battery that has superior cycle life and safety and reduced internal resistance of the battery at low temperature is provided. The positive electrode material for a nonaqueous lithium secondary battery comprise a layered structured complex oxide expressed by a composition formula LiaMnxNiyCozM?O2, where 0<a?1.2, 0.1?x?0.9, 0?y?0.44, 0.1?z?0.6, 0.01???0.1, and x+y+z+?=1. A diffraction peak intensity ratio between the (003) plane and the (104) plane (I(003)/I(104)) in an X-ray powder diffractometry using a Cu—K? line in the X-ray source is not less than 1.0 and not more than 1.5.
    Type: Application
    Filed: December 23, 2004
    Publication date: June 30, 2005
    Inventors: Toyotaka Yuasa, Masahiro Kasai
  • Publication number: 20040253516
    Abstract: The object of the invention is to provide positive electrode material in which a discharge rate characteristic and battery capacity are hardly deteriorated in the environment of low temperature of −30° C., its manufacturing method and a lithium secondary battery using the positive electrode material. The invention is characterized by the positive electrode material in which plural primary particles are flocculated and a secondary particle is formed, and the touch length of the primary particles is equivalent to 10 to 70% of the length of the whole periphery on the section of the touched primary particles.
    Type: Application
    Filed: February 27, 2004
    Publication date: December 16, 2004
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Genei Nakajima
  • Patent number: 6316391
    Abstract: The present invention provides superconductors capable of being used at temperatures to which the superconductor can be cooled in liquid nitrogen and of carrying current in a high critical current density in a magnetic field, and superconducting apparatuses employing the superconductors and more advantageous in costs than the conventional superconducting apparatuses. A superconducting wire is formed by combining a metallic body of a cubic aggregate structure and an oxide superconducting substance. The present invention provides superconductors, superconducting wires, superconducting magnets and applied superconducting apparatuses having a high superconducting critical current density. The applied super conducting apparatuses employing the superconductors or the superconducting wires in accordance with the present invention are able to operate when cooled in liquid nitrogen-and can be manufactured at costs lower than those of the conventional superconducting apparatuses.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: November 13, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takesi Ozawa, Toyotaka Yuasa, Kazutoshi Higashiyama
  • Patent number: 5798312
    Abstract: An elongate superconductor wiring element having, as seen in section, oxide superconductor material regions in each of which the c-axes of the oxide superconductor crystals are aligned with each other and are transverse to the longitudinal axis of the element. To reduce the dependence of critical current density on angular position of the element relative to a magnetic field, there are a plurality of said regions whose alignment directions of the c-axes are different as between different ones of said regions, so that the wiring element comprises a plurality of said regions having respectively different c-axis alignment directions.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: August 25, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Michiya Okada, Kazuhide Tanaka, Toyotaka Yuasa, Toshimi Matsumoto, Katsuzo Aihara, Shinpei Matsuda
  • Patent number: 5648322
    Abstract: A superconductive material has the formula(Tl.sub.1-X1-X2 Pb.sub.X1 Bi.sub.X2).sub..alpha. (Sr.sub.1-X3 Ba.sub.X3).sub..beta. Ca.sub..gamma. Cu.sub..delta. O.sub..xi.where0.ltoreq.X1.ltoreq.0.80.ltoreq.X2.ltoreq.0.50.ltoreq.X3.ltoreq.1.00.7.ltoreq..alpha..ltoreq.1.51.4.ltoreq..beta..ltoreq.3.00.7.ltoreq..gamma..ltoreq.4.51.4.ltoreq..delta..ltoreq.64.5.ltoreq..xi..ltoreq.170<X1+X2<1.The superconducting material may be combined with an isostructural non-superconducting material, which then acts as a pinning center. The result may also be combined with a metal. The resulting superconductor permits a high critical current density Jc to be obtained, even at relatively high magnetic flux densities.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: July 15, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takeshi Ozawa, Kazuhide Tanaka, Toyotaka Yuasa, Tomoichi Kamo, Shinpei Matsuda
  • Patent number: 5462922
    Abstract: A superconductive material has the formula(Tl.sub.1-X1-x2 Pb.sub.X1 Bi.sub.X2).sub..alpha. (Sr.sub.1-X3 Ba.sub.X3).sub..beta. Ca.sub..gamma. Cu.sub..delta. O.sub..zeta.where0.ltoreq.X1.ltoreq.0.80.ltoreq.X2.ltoreq.0.50.ltoreq.X3.ltoreq.1.00.7.ltoreq..alpha..ltoreq.1.51.4.ltoreq..beta..ltoreq.3.00.7.ltoreq..gamma..ltoreq.4.51.4.ltoreq..delta..ltoreq.64.5.ltoreq..zeta..ltoreq.170<X1+X2<1.The superconducting material may be combined with an isostructural non-superconducting material, which then acts as a pinning center. The result may also be combined with a metal. The resulting superconductor permits a high critical current density Jc to be obtained, even at relatively high magnetic flux densities.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: October 31, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Toshiya Doi, Takeshi Ozawa, Kazuhide Tanaka, Toyotaka Yuasa, Tomoichi Kamo, Shinpei Matsuda
  • Patent number: 5318948
    Abstract: A high-temperature oxide superconductor is provided and comprises oxide crystals oriented in a certain direction, the oxide superconductor being substantially free of or containing a controlled amount of foreign phases, a non-superconducting phase and weak superconducting phase which are harmful for superconducting characteristics in the grains of the crystals and at the grain boundaries between the crystals. The foreign phases, if any, are finely and uniformly dispersed in the grains of the oxide crystals and at the grain boundaries. A wire made from the oxide superconductor, a coil from the wire, and a magnetic field generator from the coil are disclosed, the superconductor wire having only a single layer of oxide crystal grains in the thickness direction.
    Type: Grant
    Filed: April 13, 1992
    Date of Patent: June 7, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Michiya Okada, Ryou Nishiwaki, Yoshihide Wadayama, Toshimi Matsumoto, Katsuzo Aihara, Tomoichi Kamo, Shinpei Matsuda, Toshihide Nabatame, Yukio Saito, Toyotaka Yuasa