Patents by Inventor Takehito Mitate

Takehito Mitate 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: 5900335
    Abstract: A non-aqueous secondary battery composed of an negative electrode comprising a carbon material capable of conducting absorption-desorption or intercalation-deintercalation of lithium into or from itself, a positive electrode comprising a lithium-containing chalcogenide compound, and a non-aqueous ion conductor, in which the carbon material for the negative electrode is such that combined oxygens on its surface are substantially removed.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: May 4, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoto Nishimura, Takehito Mitate, Tetsuya Yoneda, Kazuo Yamada
  • Patent number: 5879417
    Abstract: A carbon electrode for a nonaqueous secondary battery is provided, which comprises a metal collector serving to catalyze carbon graphitization, graphite particles, and a carbon material having a lower crystallinity than the graphite particles, the graphite particles and the carbon material being sintered together on the metal collector or in the presence of the metal collector.
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: March 9, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuo Yamada, Takehito Mitate, Naoto Nishimura, Yoshihiro Tsukuda, Tetsuya Yoneda
  • Patent number: 5817436
    Abstract: The present invention provides a novel lithium nickel composite oxide represented by the composition formula (I):Li.sub.2+x Ni.sub.1-x O.sub.2+y (0.0.ltoreq.x.ltoreq.1/7, 0.0.ltoreq.y<0.3, excluding the case where x=y=0) (I),a preparation process therefor and applications thereof. Where the lithium nickel composite oxide is used as a positive-electrode active material for a nonaqueous secondary battery, high capacity charge-discharge characteristics can be ensured. The novel lithium nickel composite oxide of the present invention is promising as a catalyst, an adsorbent, a dielectric material, and a magnetic material besides such a battery material.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: October 6, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Motoaki Nishijima, Takehito Mitate
  • Patent number: 5792574
    Abstract: A nonaqueous secondary battery is provided, which comprises a positive electrode, a negative electrode and a nonaqueous ion conductor, the negative electrode containing a lithium-containing substance or a lithium insertable and releasable substance as a positive electrode active material, the positive electrode containing a lithium nickelate compound as a positive electrode substance, wherein the lithium nickelate compound has a layered rocksalt crystalline structure belonging to Space Group R-3m and the ratio of a 3a- and 3b-site occupation rate of lithium atoms to a 3a- and 3b-site occupation rate of nickel atoms in the crystal lattice thereof is 0.85 to 1.15.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: August 11, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takehito Mitate, Motoaki Nishijima, Yoshihiro Tsukuda, Kazuo Yamada
  • Patent number: 5776610
    Abstract: A method for manufacturing a carbon composite electrode material which comprises coating the surface of core carbon particles with high crystallinity with a film containing a element of Group VIII metal and depositing and/or covering the surface of resulting coated carbon particles with a carbon material to be formed upon pyrolysis of a hydrocarbon or its derivative.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: July 7, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuo Yamada, Hideaki Tanaka, Takehito Mitate, Masaharu Yoshikawa
  • Patent number: 5723232
    Abstract: A carbon electrode for a nonaqueous secondary battery is provided, which comprises a metal collector serving to catalyze carbon graphitization, graphite particles, and a carbon material having a lower crystallinity than the graphite particles, the graphite particles and the carbon material being sintered together on the metal collector or in the presence of the metal collector.
    Type: Grant
    Filed: April 1, 1996
    Date of Patent: March 3, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuo Yamada, Takehito Mitate, Naoto Nishimura, Yoshihiro Tsukuda, Tetsuya Yoneda
  • Patent number: 5702843
    Abstract: A nonaqueous secondary battery is provided which comprises a positive electrode, a negative electrode and a nonaqueous ion conductor, either one of the positive electrode and the negative electrode containing lithium or a lithium absorbable and desorbable substance as an active material thereof, the other electrode containing a lithium transition-metal nitride of an anti-fluorite type structure as an active material thereof.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: December 30, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takehito Mitate, Motoaki Nishijima
  • Patent number: 5595838
    Abstract: A method for manufacturing a carbon composite electrode material which comprises coating the surface of core carbon particles with high crystallinity with a film containing a element of Group VIII metal and depositing and/or covering the surface of resulting coated carbon particles with a carbon material to be formed upon pyrolysis of a hydrocarbon or its derivative.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: January 21, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuo Yamada, Hideaki Tanaka, Takehito Mitate, Masaharu Yoshikawa
  • Patent number: 5591547
    Abstract: A method of manufacturing a negative electrode for a lithium secondary battery includes the steps of mixing graphite particles as a main constituent that generates intercalation and de-intercalation of lithium ions with a compound including copper ions, obtaining graphite composite powder having copper oxide particles formed at least on a part of the surface of at least a part of the graphite particles by chemical reaction of the copper ions, and mixing the graphite composite powder with a binding material.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: January 7, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tetsuya Yoneda, Takehito Mitate, Naoto Nishimura, Kazuo Yamada
  • Patent number: 5589299
    Abstract: A carbon electrode for a nonaqueous secondary battery comprising a conductive substrate doubling as a collector and carbon formed directly thereon, wherein the conductive substrate comprises a metal or a compound thereof having a catalytic action with respect to graphitization of a carbon material at a portion where carbon is required to be formed from a carbon precursor and comprises a metal or a compound thereof having no catalytic action with respect to graphitization of the carbon material at a portion where carbon is not required to be formed from the carbon source.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: December 31, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuo Yamada, Takehito Mitate, Tetsuya Yoneda, Naoto Nishimura
  • Patent number: 5576121
    Abstract: A lithium secondary battery is disclosed which comprises: a positive electrode; a negative electrode; and a nonaqueous ion conductor, the negative electrode including a primary negative-electrode active material of a graphite which is capable of intercalation and deintercalation of lithium ions, and a secondary negative-electrode active material of a cupric oxide having a low crystallinity.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: November 19, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuo Yamada, Takehito Mitate, Tetsuya Yoneda, Naoto Nishimura
  • Patent number: 5482797
    Abstract: A nonaqueous secondary battery comprising a cathode, an anode and a nonaqueous electrolyte disposed and sealed between the cathode and the anode wherein the anode is made of a carbon material as its active material, in which the carbon material comprises a fine core particle of a metal or an alloy thereof, and a carbon layer which is arranged and stacked in an onion-like shell configuration centering on the fine core particle, at least part of the carbon layer having a crystal structure in which graphite-like layers are stacked and the fine core particle having an average diameter of about 10 to 150 nm.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: January 9, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuo Yamada, Hideaki Tanaka, Tetsuya Yoneda, Takehito Mitate, Hiroyuki Kitayama
  • Patent number: 5478672
    Abstract: A nonaqueous secondary battery comprising: a positive electrode; a negative electrode; and a nonaqueous ion conductor; the negative electrode comprising an active material which contains lithium or enables lithium to intercalate/deintercalate or insertion/desertion; the positive electrode comprising an active material which is a lithium manganese composite oxide having an X-ray diffraction pattern using a CuK.alpha.-ray which shows at least three peaks in the ranges between 15.2.degree. and 15.6.degree., between 18.6.degree. and 18.8.degree., and between 24.5.degree. and 25.1.degree., the ratio of a peak intensity in the range between 27.degree. and 33.degree. to a peak intensity in the range between 15.2.degree. and 15.6.degree. being less than 0.02.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: December 26, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Takehito Mitate
  • Patent number: 5478364
    Abstract: The lithium secondary battery includes a positive electrode, a nonaqueous ion conductive medium, and a negative electrode, and the negative electrode includes as a main constituent graphite which permits intercalation and deintercalation of lithium ions, together with copper oxide and a binder.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: December 26, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takehito Mitate, Naoto Nishimura, Akimasa Umemoto, Hiroshi Okamoto, Kazuo Yamada, Tetsuya Yoneda
  • Patent number: 5432029
    Abstract: The lithium secondary battery includes a positive electrode, a nonaqueous ion conductive medium, and a negative electrode, and the negative electrode includes as a main constituent graphite which permits intercalation and deintercalation of lithium ions, together with copper oxide and a binder.
    Type: Grant
    Filed: May 13, 1994
    Date of Patent: July 11, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takehito Mitate, Naoto Nishimura, Akimasa Umemoto, Hiroshi Okamoto, Kazuo Yamada, Tetsuya Yoneda
  • Patent number: 5407762
    Abstract: A non-aqueous secondary battery of the present invention includes a positive electrode; a negative electrode containing lithium, and a non-aqueous ion-conductive material, wherein the positive electrode contains Li.sub.x Co.sub.1-y Sb.sub.y O.sub.2, where 0.05.ltoreq.x.ltoreq.1.1, and 0.001.ltoreq.y.ltoreq.0.10 as a positive electrode active material.
    Type: Grant
    Filed: December 21, 1992
    Date of Patent: April 18, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takehito Mitate, Akimasa Umemoto, Tetsuya Yoneda, Masaharu Yoshikawa
  • Patent number: 5344726
    Abstract: A carbon anode for a secondary battery in which a carbon active material of the carbon anode is covered with an amorphous carbon.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: September 6, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hideaki Tanaka, Takehito Mitate, Hiroyuki Kitayama, Kuzuo Yamada