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).

  • Patent number: 8263269
    Abstract: The present invention provides a lithium secondary battery which has improved safety, mainly coming from use of an electrolyte solution which is not inflammable at room temperature (20° C.), while not deteriorating output characteristics at low temperatures and room temperature or output maintenance characteristics after storage at high temperature (50° C.). The lithium secondary battery of the present invention, encased in a container, is provided with a cathode and an anode, both capable of storing/releasing lithium ions, a separator which separates these electrodes from each other, and an electrolyte solution containing a cyclic carbonate and a linear carbonate as solvents and a compound such as VC at composition ratios of 18.0 to 30.0%, 74.0 to 81.9% and 0.1 to 1.0%, respectively, based on the whole solvents, all percentages by volume.
    Type: Grant
    Filed: August 3, 2010
    Date of Patent: September 11, 2012
    Assignee: Hitachi Vehicle Energy, Ltd.
    Inventors: Takefumi Okumura, Takahiro Yamaki, Masanori Yoshikawa, Yoshimi Yanai, Toyotaka Yuasa
  • Publication number: 20120183839
    Abstract: The present invention provides a high-output lithium secondary battery. A cathode for lithium ion secondary battery of the present invention is used for a lithium secondary battery including a non-aqueous electrolyte solution. The cathode includes a complex oxide having an olivine structure represented by a chemical formula LiaMxPO4 (0<a?1.2, 0.9?x?1.1, and M is a transition metal including Fe or Mn), where a peak intensity ratio (I(020)/I(101)) between (020) and (101) of the cathode measured by X-ray diffraction using Cu—K? radiation is 3.5 or more and 4.2 or less, and is preferably 3.8 or more and 4.2 or less. Preferably, the cathode material has a primary particle diameter of between 20 nm and 200 nm, and a specific surface area of between 10 m2/g and 30 m2/g.
    Type: Application
    Filed: July 28, 2010
    Publication date: July 19, 2012
    Inventors: Toyotaka Yuasa, Mituru Kobayasi, Sai Ogawa
  • Patent number: 8097363
    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: Grant
    Filed: February 8, 2011
    Date of Patent: January 17, 2012
    Assignees: Hitachi, Ltd., Hitachi Metals, Ltd., Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Genei Nakajima
  • Publication number: 20120003542
    Abstract: A high safety cathode active material having large capacity, suppressing deterioration in storage at high temperature, and ensuring thermal stability in a charged state is provided. A cathode active material represented by a composition formula of LixNiaMnbCocM1dM2eO2 where M1 is at least one or more kinds of elements selected from the group consisting of Al, Ti, and Mg; M2 is at least one or more kinds of elements selected from the group consisting of Mo, W, and Nb; 0.2?x?1.2; 0.6?a?0.8; 0.05?b?0.3; 0.05?c?0.3; 0.02?d?0.04; 0.02?e?0.06; and a+b+c+d+e=1.0 is used.
    Type: Application
    Filed: June 29, 2011
    Publication date: January 5, 2012
    Inventors: Hiroaki KONISHI, Toyotaka Yuasa, Masanori Yoshikawa
  • Publication number: 20110189541
    Abstract: It is an object to provide a cathode for a secondary lithium battery in which adhesiveness and flexibility thereof are simultaneously achieved and the thickness thereof is made large, and the secondary lithium ion battery that has a large capacity and is excellent in safety and cycle life using the cathode. The cathode includes a current collector and a cathode mixture layer formed on the surface of the current collector. The cathode mixture layer is formed by stacking two layers one on another, each of which contains a cathode active material, a conductive material and a binder, and the cathode active material contains a lithium-containing composite oxide that forms a polyanion.
    Type: Application
    Filed: January 27, 2011
    Publication date: August 4, 2011
    Inventors: Kan KITAGAWA, Toyotaka Yuasa, Tatsuya Tooyama
  • Publication number: 20110127463
    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 8, 2011
    Publication date: June 2, 2011
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Genei Nakajima
  • Publication number: 20110129734
    Abstract: A lithium ion secondary battery according to the present invention uses a cathode material obtained by mixing a first cathode active substance represented by a compositional formula: Lix1Nia1Mnb1COc1O2 (in which 0.2?x1?1.2, 0.6?a1?0.9, 0.05?b1?0.3, 0.05?c1?0.3, and a1+b1+c1=1.0); and a second cathode active substance represented by a compositional formula: Lix2Nia2Mnb2COc2MdO2 (in which 0.2?x2?1.2, 0.7?a2?0.9, 0.05?b2?0.3, 0.05?c2?0.3, M=Mo, W, 0?d?0.06, and a2+b2+c2+d=1.0).
    Type: Application
    Filed: August 20, 2010
    Publication date: June 2, 2011
    Inventors: Hiroaki Konishi, Toyotaka Yuasa
  • Patent number: 7910246
    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: Grant
    Filed: February 27, 2004
    Date of Patent: March 22, 2011
    Assignees: Hitachi, Ltd., Hitachi Metals, Ltd., Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Genei Nakajima
  • Patent number: 7862933
    Abstract: The present invention provides a lithium secondary battery which has improved safety, mainly coming from use of an electrolyte solution which is not inflammable at room temperature (20° C.), while not deteriorating output characteristics at low temperatures and room temperature or output maintenance characteristics after storage at high temperature (50° C.). The lithium secondary battery of the present invention, encased in a container, is provided with a cathode and an anode, both capable of storing/releasing lithium ions, a separator which separates these electrodes from each other, and an electrolyte solution containing a cyclic carbonate and a linear carbonate as solvents and a compound such as VC at composition ratios of 18.0 to 30.0%, 74.0 to 81.9% and 0.1 to 1.0%, respectively, based on the whole solvents, all percentages by volume.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: January 4, 2011
    Assignee: Hitachi Vehicle Energy, Ltd.
    Inventors: Takefumi Okumura, Takahiro Yamaki, Masanori Yoshikawa, Yoshimi Yanai, Toyotaka Yuasa
  • Publication number: 20100297509
    Abstract: The present invention provides a lithium secondary battery which has improved safety, mainly coming from use of an electrolyte solution which is not inflammable at room temperature (20° C.), while not deteriorating output characteristics at low temperatures and room temperature or output maintenance characteristics after storage at high temperature (50° C.). The lithium secondary battery of the present invention, encased in a container, is provided with a cathode and an anode, both capable of storing/releasing lithium ions, a separator which separates these electrodes from each other, and an electrolyte solution containing a cyclic carbonate and a linear carbonate as solvents and a compound such as VC at composition ratios of 18.0 to 30.0%, 74.0 to 81.9% and 0.1 to 1.0%, respectively, based on the whole solvents, all percentages by volume.
    Type: Application
    Filed: August 3, 2010
    Publication date: November 25, 2010
    Inventors: Takefumi Okumura, Takahiro Yamaki, Masanori Yoshikawa, Yoshimi Yanai, Toyotaka Yuasa
  • Publication number: 20100297503
    Abstract: A positive electrode for lithium secondary batteries and a lithium secondary battery are provided in which, by using an olivine Mn based positive-electrode active material and an optimal binder for the olivine Mn based positive-electrode active material, peel-off of the electrode and gelatinization of the slurry can be prevented, with large energy density, excellent in rate characteristic and cycle life. The positive electrode includes a positive-electrode composite including at least a positive-electrode active material and a binder; and a positive-electrode current collector. The positive-electrode active material includes a lithium composite oxide having an olivine-type structure, which is represented by the formula LiMnxM1?xPO4 (where 0.3?x?1 and M is one or more elements selected from the group consisting of Li, Fe, Ni, Co, Ti, Cu, Zn, Mg, and Zr) . The binder includes an acrylonitrile-based copolymer.
    Type: Application
    Filed: May 20, 2010
    Publication date: November 25, 2010
    Inventors: Kan Kitagawa, Atsushi Ueda, Toyotaka Yuasa, Tatsuya Toyama
  • Patent number: 7824807
    Abstract: A positive electrode material for lithium secondary battery having high electron conductivity even at very low temperatures and a lithium secondary battery with the use of the positive electrode material are provided. The positive electrode material for lithium secondary battery has secondary particles formed of primary particles made of lithium complex oxides composited with ultrathin carbon fibers having lengths equal to or smaller than the diameters of the secondary particles of the positive electrode active material. The ultrathin carbon fibers have opposite ends from which an electrolytic solution moves in and out.
    Type: Grant
    Filed: December 8, 2005
    Date of Patent: November 2, 2010
    Assignee: Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Sai Ogawa
  • Publication number: 20100261061
    Abstract: A positive electrode material for a lithium secondary battery according to the invention includes a positive electrode active material containing lithium oxide and a carbon composite obtained by dispersing carbon fiber and a clamped shape carbon material, and the positive electrode active material is combined with the carbon composite. In the positive electrode material for a lithium secondary battery constructed as described above, a conductive network between primary particles is formed by the carbon composite while the positive electrode active material (primary particles) are condensed to form secondary particles.
    Type: Application
    Filed: August 11, 2006
    Publication date: October 14, 2010
    Inventors: Toyotaka Yuasa, Sai Ogawa, Hirofumi Takahashi
  • Publication number: 20100221609
    Abstract: This invention provides a positive electrode material having high capacity and safety, and a lithium ion secondary battery using the positive electrode material, the lithium ion secondary battery using a positive electrode active substance comprising a first transition metal oxide represented by the compositional formula: Lix1Nia1Mnb1Coc1Md1O2; a second transition metal oxide represented by the compositional formula: Lix2Nia2Mnb2Coc2Md2O2; and a third transition metal oxide represented by the compositional formula: Lix3Nia3Mnb3Coc3Md3O2; in which a3<a2<a1.
    Type: Application
    Filed: January 29, 2010
    Publication date: September 2, 2010
    Applicant: Hitachi, Ltd.
    Inventors: Hiroaki KONISHI, Toyotaka YUASA
  • Publication number: 20100081055
    Abstract: A cathode material with excellent capacity and output characteristics and safety, and a lithium ion secondary battery using the same is provided. The invention relates to a cathode material which includes a mixture of a cathode active material having a large primary particle size with excellent capacity characteristics and represented by the composition formula: Lix1Nia1Mnb1Coc1O2, where 0.2?x1?1.2, 0.6?a1, 0.05?b1?0.3, 0.05?c1?0.3, and another cathode active material having a small primary particle size with excellent output characteristics and represented by the composition formula: Lix2Nia2Mnb2Coc2O2, where 0.2?x2 ?1.2, a2?0.5, 0.05?b2?0.5, 0.05?c2?0.5. The invention also relates to a lithium ion secondary battery using the cathode material.
    Type: Application
    Filed: August 18, 2009
    Publication date: April 1, 2010
    Inventors: Hiroaki KONISHI, Toyotaka YUASA, Mitsuru KOBAYASHI
  • Patent number: 7604898
    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: Grant
    Filed: May 8, 2007
    Date of Patent: October 20, 2009
    Assignees: Hitachi, Ltd., Hitachi Metals, Ltd., Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Toyotaka Yuasa, Masahiro Kasai, Genei Nakajima
  • Patent number: 7582383
    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: Grant
    Filed: August 26, 2005
    Date of Patent: September 1, 2009
    Assignee: Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Masahiro Kasai, Toyotaka Yuasa
  • Publication number: 20090104517
    Abstract: Disclosed herein are a cathode material for a lithium secondary battery capable of attaining high power and high capacitance simultaneously, and a lithium secondary battery using the same. A cathode material for a lithium secondary battery in which a primary particle constituting a secondary particle of a cathode active material comprises a particle mainly having a particle size of more than 0.1 ?m and less than 0.5 ?m, a specific surface area of the secondary particle is 1.1 m2/g or more and 1.6 m2/g or less, and the narrowest diameter for through pores of the secondary particle as measured by a Perm Porometry is more than 0.1 ?m and less than 0.3 ?m.
    Type: Application
    Filed: October 10, 2008
    Publication date: April 23, 2009
    Inventors: Toyotaka YUASA, Mituru Kobayasi, Sai Ogawa
  • Patent number: 7517613
    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: Grant
    Filed: December 23, 2004
    Date of Patent: April 14, 2009
    Assignee: Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Toyotaka Yuasa, Masahiro Kasai
  • Publication number: 20080241701
    Abstract: The present invention provides a lithium secondary battery which has improved safety, mainly coming from use of an electrolyte solution which is not inflammable at room temperature (20° C.), while not deteriorating output characteristics at low temperatures and room temperature or output maintenance characteristics after storage at high temperature (50° C.). The lithium secondary battery of the present invention, encased in a container, is provided with a cathode and an anode, both capable of storing/releasing lithium ions, a separator which separates these electrodes from each other, and an electrolyte solution containing a cyclic carbonate and a linear carbonate as solvents and a compound such as VC at composition ratios of 18.0 to 30.0%, 74.0 to 81.9% and 0.1 to 1.0%, respectively, based on the whole solvents, all percentages by volume.
    Type: Application
    Filed: January 25, 2008
    Publication date: October 2, 2008
    Inventors: Takefumi Okumura, Takahiro Yamaki, Masanori Yoshikawa, Yoshimi Yanai, Toyotaka Yuasa