Patents by Inventor Hideharu Takezawa

Hideharu Takezawa 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: 8734997
    Abstract: A negative electrode 100 for a nonaqueous electrolytic secondary cell includes a current collector 1 and a plurality of active material bodies 2 formed on a surface of the current collector 1 at intervals; each active material body 2 contains a material for occluding or releasing lithium; and a plurality of projections 3 are formed on a part of a side surface of each active material body 2.
    Type: Grant
    Filed: October 9, 2007
    Date of Patent: May 27, 2014
    Assignee: Panasonic Corporation
    Inventors: Satoshi Shibutani, Hideharu Takezawa, Kazuyoshi Honda, Toshitada Sato
  • Patent number: 8673471
    Abstract: Provided is a highly safe portable electronic device having a secondary battery as a power source, and including a housing, an electronic device body housed in the housing, and a battery housing portion housed in the housing, in which a surface is inhibited from being locally heated to high temperature. In the portable electronic device, the battery housing portion is a molding with a battery fitting portion for fitting the secondary battery therein, and the battery fitting portion has provided on its surface a heat-insulating layer having a thickness of from 500 to 3000 ?m and a thermal conductivity of 0.2 W/m·K or lower.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: March 18, 2014
    Assignee: Panasonic Corporation
    Inventors: Tomohiko Yokoyama, Hideharu Takezawa, Kazuya Iwamoto, Taisuke Yamamoto
  • Publication number: 20130314051
    Abstract: A charge/discharge method for a lithium secondary battery is performed on a lithium secondary battery including a positive electrode containing a positive electrode active material capable of occluding/releasing lithium ions; a negative electrode containing a negative electrode active material capable of occluding/releasing lithium ions; a separator located between the positive electrode and the negative electrode; and an electrolyte having a lithium ion conductivity. The positive electrode active material contains a lithium-containing transition metal oxide; and a reversible capacity of the negative electrode is larger than a usable capacity of the positive electrode. First charge/discharge is performed by which the positive electrode in a charged state is discharged until having a first potential VDp1, which is lower than 2.7 V on a lithium metal basis, and the discharge is finished at this point.
    Type: Application
    Filed: January 13, 2012
    Publication date: November 28, 2013
    Applicant: PANASONIC CORPORATION
    Inventor: Hideharu Takezawa
  • Patent number: 8586233
    Abstract: Provided is a highly safe portable electronic device having a secondary battery as a power source, and including a package, an electronic device body housed in the package, and a battery housing portion housed in the package, in which even if the content melts due to an extremely significant impact applied thereto, discharge of a melt is inhibited. In the portable electronic device, the battery housing portion is a molding with a battery fitting portion for fitting the secondary battery therein, and the battery fitting portion has a covering layer, which includes a temperature suppression layer and a block layer, provided on its surface.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: November 19, 2013
    Assignee: Panasonic Corporation
    Inventors: Hideharu Takezawa, Tomohiko Yokoyama, Kazuya Iwamoto, Taisuke Yamamoto
  • Publication number: 20130302688
    Abstract: A lithium secondary battery according to the present invention includes a positive electrode containing a positive electrode active material capable of occluding/releasing lithium ions; a negative electrode containing a negative electrode active material capable of occluding/releasing lithium ions; a separator located between the positive electrode and the negative electrode; and an electrolyte having a lithium ion conductivity. The positive electrode active material contains a lithium nickel complex oxide substantially having an irreversible capacity; the negative electrode active material has lithium occluded thereto in advance; and in a completely discharged state of the lithium secondary battery when an environmental temperature is 25° C., an amount of lithium releasable from the negative electrode is larger than an irreversible capacity of the lithium secondary battery.
    Type: Application
    Filed: January 13, 2012
    Publication date: November 14, 2013
    Applicant: PANASONIC CORPORATION
    Inventor: Hideharu Takezawa
  • Patent number: 8568925
    Abstract: A lithium secondary battery according to the present invention includes: a positive electrode having a positive-electrode active material capable of occluding and releasing lithium ions; a negative electrode having a negative-electrode active material capable of occluding and releasing lithium ions; a separator interposed between the positive electrode and the negative electrode; and an electrolyte having lithium-ion conductivity. The positive-electrode active material contains a nickel-type lithium-containing complex oxide. The negative-electrode active material contains a graphite-type material having a reversible capacity of 350 mAh/g or more and an irreversible capacity of 30 mAh/g or less. A ratio Qc/Qa between an irreversible capacity Qc per unit area in a portion of the positive electrode that opposes the negative electrode and an irreversible capacity Qa per unit area in a portion of the negative electrode that opposes the positive electrode is equal to or greater than 0.50 but less than 1.
    Type: Grant
    Filed: May 12, 2011
    Date of Patent: October 29, 2013
    Assignee: Panasonic Corporation
    Inventors: Taisuke Yamamoto, Hideharu Takezawa
  • Patent number: 8389163
    Abstract: A lithium secondary battery includes a positive electrode including a positive electrode active material, a negative electrode including a negative electrode active material, and a non-aqueous electrolyte. The positive electrode active material comprises at least one lithium-containing composite oxide represented by the following general formula: LixM11?yM2yO2 where M1 and M2 are different elements, M1 is Ni or Co, M2 is at least one selected from Ni, Co, Mn, Mg, and Al, 1?x?1.05, and 0?y?0.7. The negative electrode active material comprises at least one selected from the group consisting of silicon, tin, a silicon-containing alloy, and a tin-containing alloy. The non-aqueous electrolyte includes an organic peroxide.
    Type: Grant
    Filed: March 14, 2005
    Date of Patent: March 5, 2013
    Assignee: Panasonic Corporation
    Inventor: Hideharu Takezawa
  • Patent number: 8318347
    Abstract: In a lithium ion secondary battery including a flat-plate electrode assembly which is configured by stacking the positive electrode, the separator, and the negative electrode in the thickness direction thereof, each of the positive electrode and the negative electrode includes a current collector and an active material layer. Each of the current collector includes a substantially rectangular current collector body, a heat radiating portion, and a lead portion, and the heat radiating portions are projected toward the outside of the electrode assembly so as not to overlap with each other in the thickness direction of the electrode assembly. In this way, heat caused inside the lithium ion secondary battery can be diffused efficiently to the outside, and safety of the lithium ion secondary battery can be further increased, without complicating the battery structure and decreasing mechanical strength of the battery.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: November 27, 2012
    Assignee: Panasonic Corporation
    Inventors: Tomohiko Yokoyama, Masato Fujikawa, Hideharu Takezawa, Shinji Kasamatsu
  • Patent number: 8273136
    Abstract: A method for manufacturing an electrode of an electrochemical element includes: (A) forming an active material layer on a current collector; and (B) providing lithium to the active material layer. The A step and the B step are carried out in continuous space.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: September 25, 2012
    Assignee: Panasonic Corporation
    Inventors: Hideharu Takezawa, Toshitada Sato, Kazuyoshi Honda
  • Patent number: 8257869
    Abstract: An electrode for an electrochemical element reversibly absorbing and releasing lithium ions including: a current collector having a higher first convex portion and a lower second convex portion on at least one surface thereof; a columnar body including an active material formed in such a manner as to rise obliquely on the first convex portion and the second convex portion of the current collector.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: September 4, 2012
    Assignee: Panasonic Corporation
    Inventors: Hideharu Takezawa, Shoichi Imashiku, Kaoru Nagata, Takashi Otsuka
  • Publication number: 20120208087
    Abstract: A lithium secondary battery according to the present invention includes: a positive electrode having a positive-electrode active material capable of occluding and releasing lithium ions; a negative electrode having a negative-electrode active material capable of occluding and releasing lithium ions; a separator interposed between the positive electrode and the negative electrode; and an electrolyte having lithium-ion conductivity. The positive-electrode active material contains a nickel-type lithium-containing complex oxide. The negative-electrode active material contains a graphite-type material having a reversible capacity of 350 mAh/g or more and an irreversible capacity of 30 mAh/g or less. A ratio Qc/Qa between an irreversible capacity Qc per unit area in a portion of the positive electrode that opposes the negative electrode and an irreversible capacity Qa per unit area in a portion of the negative electrode that opposes the positive electrode is equal to or greater than 0.50 but less than 1.13.
    Type: Application
    Filed: May 12, 2011
    Publication date: August 16, 2012
    Inventors: Taisuke Yamamoto, Hideharu Takezawa
  • Publication number: 20120176097
    Abstract: In a charge/discharge method for a positive-electrode active material in a lithium secondary battery, the lithium secondary battery includes a positive electrode containing a positive-electrode active material capable of occluding and releasing lithium ions, a negative electrode containing a negative-electrode active material capable of occluding and releasing lithium ions, a separator located between the positive electrode and the negative electrode, and an electrolyte having a lithium ion conductivity; and the positive-electrode active material contains a nickel-type lithium-containing complex oxide. The positive electrode, which has been charged, is discharged until having a first potential VDp1 which is no less than 2.7 V and no more than 3.4 V on a lithium metal basis, and then the discharge is finished. Owing to this, the charge/discharge cycle life can be improved while the capacity of the lithium secondary battery is secured.
    Type: Application
    Filed: September 17, 2010
    Publication date: July 12, 2012
    Inventors: Hideharu Takezawa, Kazuya Iwamoto, Taisuke Yamamoto, Masaya Ugaji, Tatsuki Hiraoka
  • Patent number: 8192864
    Abstract: In a method for examining a negative electrode of a battery, a total thickness of a current collector and an active material layer is measured. Then, in order to estimate a composition of the active material layer, the total resistivity of the current collector and the active material layer is measured.
    Type: Grant
    Filed: February 1, 2008
    Date of Patent: June 5, 2012
    Assignee: Panasonic Corporation
    Inventors: Hideharu Takezawa, Takayuki Shirane, Shinya Fujimura, Sadayuki Okazaki, Kazuyoshi Honda
  • Patent number: 8187748
    Abstract: A non-aqueous electrolyte secondary battery including: a positive electrode having a positive electrode material mixture containing a composite lithium oxide; a negative electrode; a polyolefin separator; a non-aqueous electrolyte; and a heat-resistant insulating layer interposed between the positive and negative electrodes. The positive electrode material mixture has an estimated heat generation rate at 200° C. of not greater than 50 W/kg. The positive electrode and the negative electrode are wound together with the separator and the heat-resistant insulating layer interposed therebetween.
    Type: Grant
    Filed: June 23, 2006
    Date of Patent: May 29, 2012
    Assignee: Panasonic Corporation
    Inventors: Hajime Nishino, Shinji Kasamatsu, Hideharu Takezawa, Kazuhiro Okamura, Mikinari Shimada
  • Patent number: 8153292
    Abstract: According to a method for manufacturing an electrode of an electrochemical device, an electrode precursor capable of absorbing and releasing lithium is provided with lithium, and the resistance of the electrode precursor is measured after absorbing lithium. In addition, a processing apparatus for an electrode of an electrochemical device includes a lithium providing section for providing lithium to such an electrode precursor, and a first measurement section for measuring the resistance of the electrode precursor after absorbing lithium.
    Type: Grant
    Filed: April 10, 2008
    Date of Patent: April 10, 2012
    Assignee: Panasonic Corporation
    Inventor: Hideharu Takezawa
  • Patent number: 8148018
    Abstract: A method of manufacturing a negative electrode for a non-aqueous electrolyte secondary battery includes a step of imparting lithium to a precursor of the negative electrode capable of storing and releasing lithium, by a film forming method in a dry process. In this step, the precursor is brought into contact with a measuring terminal having a non-aqueous electrolyte and a counter electrode. The amount of lithium stored in the precursor is calculated from an open circuit potential of the precursor with respect to the counter electrode. Further, according to the calculated amount of stored lithium, the amount of lithium to be imparted to the precursor is controlled.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: April 3, 2012
    Assignee: Panasonic Corporation
    Inventor: Hideharu Takezawa
  • Patent number: 8148012
    Abstract: In a method for manufacturing a negative electrode for a battery, an active material layer including a metallic element M and an element A that is at least any one of oxygen, nitrogen, and carbon is formed on a current collector. This active material layer is irradiated with an X-ray and at least one of intensity of a K? ray of the element A and intensity of a K? ray of the metallic element M in fluorescent X-rays generated from the active material layer is measured.
    Type: Grant
    Filed: February 1, 2008
    Date of Patent: April 3, 2012
    Assignee: Panasonic Corporation
    Inventors: Hideharu Takezawa, Takayuki Shirane, Shinya Fujimura, Sadayuki Okazaki, Kazuyoshi Honda
  • Publication number: 20120070740
    Abstract: Disclosed is a negative electrode for a lithium ion secondary battery, the negative electrode including a negative electrode current collector with protrusions formed on a surface thereon, and columnar bodies being carried on the protrusions and comprising an alloy active material capable of absorbing and releasing lithium ions. The columnar bodies each have a multilayer structure in which a plurality of unit layers comprising the alloy active material are stacked sequentially on the surface of the protrusion, and the average layer thickness of the unit layer in a region within 20% of the thickness of the columnar body extending from the surface of the protrusion is smaller than that in a region within 80% of the thickness of the columnar body extending from the top of the columnar body.
    Type: Application
    Filed: March 16, 2011
    Publication date: March 22, 2012
    Inventors: Katsumi Kashiwagi, Hideharu Takezawa, Masaya Ugaji
  • Patent number: 8133374
    Abstract: A method for manufacturing a negative electrode for a non-aqueous electrolyte secondary battery is provided. A negative electrode precursor of the non-aqueous electrolyte secondary battery is allowed to absorb lithium ions, the negative electrode precursor includes a current collector and an active material layer formed on the current collector. The precursor is provided with an exposed portion of the current collector. In this method, a negative electrode active material layer is allowed to absorb lithium ions by electrolysis in the non-aqueous electrolyte solution. At this time, by measuring a potential of a portion immersed in the non-aqueous electrolyte solution, the exposed portion is detected and an electric current of the electrolysis is controlled. Thereby, the deposition of lithium metal on the exposed portion is suppressed.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: March 13, 2012
    Assignee: Panasonic Corporation
    Inventor: Hideharu Takezawa
  • Patent number: 8091505
    Abstract: In a method for testing a negative electrode of a secondary battery, light is irradiate to an active material layer formed on a current collector having a plurality of projections at least on one side thereof, the active material layer including first columnar bodies of active material grown obliquely from the projections. The angle is measured between the reflected light from the active material layer and a normal line parallel to the thickness direction of the current collector.
    Type: Grant
    Filed: February 1, 2008
    Date of Patent: January 10, 2012
    Assignee: Panasonic Corporation
    Inventors: Hideharu Takezawa, Shinya Fujimura, Sadayuki Okazaki, Kazuyoshi Honda