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).

  • Publication number: 20080102353
    Abstract: In a method for manufacturing a non-aqueous electrolyte secondary battery, a negative electrode having a current collector exposed portion in a portion corresponding to an outer winding end of an electrode body, metallic lithium piece is allowed to precipitate or be deposited on this current collector exposed portion, and this metallic lithium piece is joined to the other portion of the current collector exposed portion or one metallic lithium piece is joined to the other metallic lithium piece so as to fix two points of the negative electrode.
    Type: Application
    Filed: October 26, 2007
    Publication date: May 1, 2008
    Inventors: Hideharu Takezawa, Kazuyoshi Honda
  • Publication number: 20080073217
    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: Application
    Filed: September 18, 2007
    Publication date: March 27, 2008
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventor: Hideharu Takezawa
  • Publication number: 20080076017
    Abstract: A high capacity lithium secondary battery with excellent safety is provided by suppressing expansion of a negative electrode active material during charge and increasing the content of a heat-resistant resin in a separator relative to conventional one. The lithium secondary battery includes: a negative electrode active material that comprises compound particles containing at least one metal element selected from the group consisting of Si, Sn, Al, and Zn; and a separator that has a first porous layer comprising polyolefin and a second porous layer comprising a heat-resistant resin. The separator contains 10 to 60 parts by weight of the second porous layer per 100 parts by weight of the first porous layer.
    Type: Application
    Filed: March 29, 2006
    Publication date: March 27, 2008
    Inventors: Hideharu Takezawa, Shinji Kasamatsu
  • Publication number: 20070218365
    Abstract: A negative electrode for a nonaqueous electrolytic rechargeable battery capable of storing and discharging lithium ions is manufactured in the steps of forming a lithium metal layer on a carrier substrate by a gas phase method, superimposing the surface of the lithium metal layer formed on the carrier substrate on a negative electrode active material layer formed on a collecting body, storing the lithium metal layer into the negative electrode active material layer in nonaqueous electrolyte, and removing the carrier substrate from the negative electrode active material layer.
    Type: Application
    Filed: February 21, 2007
    Publication date: September 20, 2007
    Inventors: Hideharu Takezawa, Toshitada Sato
  • Publication number: 20070204457
    Abstract: A non-aqueous electrolyte secondary battery having both high capacity and long-life is provided by solving the problem of the large irreversible capacity of a negative electrode active material. The non-aqueous electrolyte secondary battery is produced by a method including the steps of: reacting lithium with a negative electrode active material by bringing a metal film that is composed mainly of lithium into contact with a surface of a negative electrode active material layer; and thereafter combining the negative electrode with a positive electrode to form an electrode assembly. The metal film composed mainly of lithium is preferably formed on a carrier that does not chemically react with lithium, and the metal film on the carrier is preferably brought into contact with the negative electrode active material layer while heating and applying a pressure thereto.
    Type: Application
    Filed: November 16, 2006
    Publication date: September 6, 2007
    Inventors: Toshitada Sato, Hideharu Takezawa, Syoichi Imashiku, Kazuyoshi Honda
  • Publication number: 20070190419
    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: LixM1l?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. At least one of the positive electrode, the negative electrode, and the non-aqueous electrolyte includes an organic peroxide. The above-mentioned combination of the positive electrode and the negative electrode makes it possible to improve battery capacity.
    Type: Application
    Filed: March 14, 2005
    Publication date: August 16, 2007
    Inventor: Hideharu Takezawa
  • Patent number: 7248023
    Abstract: A charger for a secondary battery including a positive electrode, a negative electrode including lithium-containing silicon represented by the composition formula LixSi, and an electrolyte. This charger includes: (1) a voltage detector that detects voltage of the secondary battery that is being charged; and (2) a charge controller that calculates the value x in LixSi included in the secondary battery from an output of the voltage detector and stops the charging of the secondary battery when the calculated value x reaches a predetermined threshold value. The charge controller has at least one settable threshold value including a first threshold value, and the first threshold value is 2.33 or less. The use of this charger makes it possible to charge the secondary battery such that it has a high capacity, or a higher capacity if necessary, without accelerating the deterioration of cycle life.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: July 24, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideharu Takezawa, Masaaki Kuranuki, Yasuhiko Bito
  • Publication number: 20070015058
    Abstract: A positive electrode for use in a lithium secondary battery comprises a positive electrode current collector, and a positive electrode film which is carried on the positive electrode current collector and includes a plurality of mixture layers. The positive electrode film contains, as a positive electrode active material, two or more kinds of lithium-containing compounds having exothermic initiation temperatures different from each other. At least one kind of the two or more kinds of lithium-containing compounds has the exothermic initiation temperature of 300° C. or higher. A first mixture layer of the plural mixture layers closest to the positive electrode current collector contains at least one kind of the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher.
    Type: Application
    Filed: July 14, 2006
    Publication date: January 18, 2007
    Inventors: Hideharu Takezawa, Hajime Nishino
  • Publication number: 20060286445
    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: Application
    Filed: June 23, 2006
    Publication date: December 21, 2006
    Inventors: Hajime Nishino, Shinji Kasamatsu, Hideharu Takezawa, Kazuhiro Okamura, Mikinari Shimada
  • Publication number: 20060286438
    Abstract: A lithium secondary battery including: an electrode group, a non-aqueous electrolyte and a battery case housing the electrode group and the non-aqueous electrolyte, the electrode group including a positive electrode, a negative electrode and a separator layer interposed between the positive electrode and the negative electrode, wherein an end-of-charge voltage and an end-of-discharge voltage are set in such a manner that the electrode group has an energy density of not less than 700 Wh/L, the separator layer includes a porous heat-resistant layer, and a short circuit area A produced when an internal short circuit has occurred between the positive electrode and the negative electrode, and a reduced area B of the porous heat-resistant layer that is produced by heat generation satisfy 1?(A+B)/A?10.
    Type: Application
    Filed: June 23, 2006
    Publication date: December 21, 2006
    Inventors: Masato Fujikawa, Shinji Kasamatsu, Hajime Nishino, Hideharu Takezawa, Mikinari Shimada
  • Publication number: 20060286439
    Abstract: A lithium secondary battery including: an electrode group, a non-aqueous electrolyte and a battery case housing the electrode group and the non-aqueous electrolyte, the electrode group including a positive electrode, a negative electrode and a separator layer interposed between the positive electrode and the negative electrode, wherein an end-of-charge voltage and an end-of-discharge voltage are set in such a manner that the electrode group has an energy density of not less than 700 Wh/L, the separator layer includes a porous heat-resistant layer, and a short circuit area A produced when an internal short circuit has occurred between the positive electrode and the negative electrode, and a reduced area B of the porous heat-resistant layer that is produced by heat generation satisfy 1?(A+B)/A?10.
    Type: Application
    Filed: January 26, 2006
    Publication date: December 21, 2006
    Inventors: Masato Fujikawa, Shinji Kasamatsu, Hajime Nishino, Hideharu Takezawa, Mikinari Shimada
  • Publication number: 20060286444
    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: Application
    Filed: June 23, 2006
    Publication date: December 21, 2006
    Inventors: Hajime Nishino, Shinji Kasamatsu, Hideharu Takezawa, Kazuhiro Okamura, Mikinari Shimada
  • Patent number: 7132199
    Abstract: A non-aqueous electrolyte containing propylene carbonate and 1,3-propanesultone as additives can reduce the amount of a gas evolved during storage at a high temperature of a non-aqueous electrolyte secondary cell comprising the electrolyte, a non-aqueous electrolyte containing at least one compound selected from the group consisting of vinylene carbonate, diphenyl disulfide, di-p-tolydisulfide and bis(4-methoxyphenyl)disulfide as comprising the electrolyte, and a non-aqueous electrolyte containing a combination of the above-two types of additives can provide a non-aqueous electrolyte secondary cell exhibiting excellent retention of capacity and storage stability.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: November 7, 2006
    Assignees: Matsushita Electric Industrial Co., Ltd., Ube Industries, Ltd.
    Inventors: Shigeyuki Unoki, Hajime Konishi, Katsumi Yamashita, Shoichiro Watanabe, Takashi Takeuchi, Hideharu Takezawa, Toshikazu Hamamoto, Akira Ueki, Koji Abe
  • Patent number: 7071653
    Abstract: A method for charging a non-aqueous electrolyte secondary battery, the battery comprising a positive electrode that comprises a lithium-containing composite oxide, a negative electrode, and a non-aqueous electrolyte. The method comprises the step of detecting an open-circuit-voltage of the battery to determine which of voltage regions A, B and C the detected value is included in. The region A is not smaller than a prescribed value X. The region B is smaller than the prescribed value X and larger than a prescribed value Y (Y<X). The region C is not larger than the value Y. According to the determination, charging is stopped when the detected value is included in the region A, charging is conducted when the detected value is included in the region B, or discharging is conducted until a closed-circuit-voltage of the battery becomes not larger than a prescribed value Z and then charging is conducted, when the detected value is included in the region C.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: July 4, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kohei Suzuki, Masato Fujikawa, Hideharu Takezawa, Katsumi Kozu
  • Publication number: 20060141341
    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 active material mixture has an estimated heat generation rate at 200° C. of not greater than 50 W/kg. The estimated heat generation rate is determined by obtaining a relation between absolute temperature T and heat generation rate V of the positive electrode material mixture using an accelerating rate calorimeter; plotting a relation between the inverse of absolute temperature T and the logarithm of heat generation rate V according to the Arrhenius law; obtaining a straight line fitted to the plotted points in a heat generation temperature range of T<200° C.; and extrapolating the straight line to the temperature of 200° C.
    Type: Application
    Filed: December 23, 2005
    Publication date: June 29, 2006
    Inventors: Hajime Nishino, Shinji Kasamatsu, Hideharu Takezawa, Kazuhiro Okamura, Mikinari Shimada
  • Publication number: 20050237029
    Abstract: A charger for a secondary battery including a positive electrode, a negative electrode including lithium-containing silicon represented by the composition formula LixSi, and an electrolyte. This charger includes: (1) a voltage detector that detects voltage of the secondary battery that is being charged; and (2) a charge controller that calculates the value x in LixSi included in the secondary battery from an output of the voltage detector and stops the charging of the secondary battery when the calculated value x reaches a predetermined threshold value. The charge controller has at least one settable threshold value including a first threshold value, and the first threshold value is 2.33 or less. The use of this charger makes it possible to charge the secondary battery such that it has a high capacity, or a higher capacity if necessary, without accelerating the deterioration of cycle life.
    Type: Application
    Filed: April 19, 2005
    Publication date: October 27, 2005
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO.,LTD.
    Inventors: Hideharu Takezawa, Masaaki Kuranuki, Yasuhiko Bito
  • Publication number: 20040241534
    Abstract: A method for charging a non-aqueous electrolyte secondary battery, the battery comprising a positive electrode that comprises a lithium-containing composite oxide, a negative electrode, and a non-aqueous electrolyte. The method comprises the step of detecting an open-circuit-voltage of the battery to determine which of voltage regions A, B and C the detected value is included in. The region A is not smaller than a prescribed value X. The region B is smaller than the prescribed value X and larger than a prescribed value Y (Y<X). The region C is not larger than the value Y. According to the determination, charging is stopped when the detected value is included in the region A, charging is conducted when the detected value is included in the region B, or discharging is conducted until a closed-circuit-voltage of the battery becomes not larger than a prescribed value Z and then charging is conducted, when the detected value is included in the region C.
    Type: Application
    Filed: May 21, 2004
    Publication date: December 2, 2004
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Kohei Suzuki, Masato Fujikawa, Hideharu Takezawa, Katsumi Kozu
  • Publication number: 20040091786
    Abstract: A non-aqueous electrolyte containing propylene carbonate and 1,3-propanesultone as additives can reduce the amount of a gas evolved during storage at a high temperature of a non-aqueous electrolyte secondary cell comprising the electrolyte, a non-aqueous electrolyte containing at least one compound selected from the group consisting of vinylene carbonate, diphenyl disulfide, di-p-tolyldisulfide and bis(4-methoxyphenyl)disulfide as an additive can improve cycle characteristics of a non-aqueous electrolyte secondary cell comprising the electrolyte, and a non-aqueous electrolyte containing a combination of the above two types of additives can provide a non-aqueous electrolyte secondary cell exhibiting excellent retention of capacity and storage stability.
    Type: Application
    Filed: December 20, 2002
    Publication date: May 13, 2004
    Inventors: Shigeyuki Unoki, Hajime Konishi, Katsumi Yamashita, Shoichiro Watanabe, Takeshi Takeuchi, Hideharu Takezawa, Akira Ueki, Toshikazu Hamamoto, Koji Abe
  • Patent number: 6733927
    Abstract: In a non-aqueous electrolyte secondary battery, the reaction between the non-aqueous electrolyte and the electrode is suppressed to reduce a decrease in the discharge capacity with the charge/discharge cycle progress and the deterioration of battery characteristics during high-temperature storage. At least one of a chargeable and dischargeable positive electrode, a non-aqueous electrolyte containing a lithium salt, and a chargeable and dischargeable negative electrode in a non-aqueous electrolyte secondary battery contains at least one selected from the group consisting of a phosphate having three aliphatic hydrocarbon groups having 7 to 12 carbon atoms, a phosphate having two aliphatic hydrocarbon groups having 1 to 12 carbon atoms or an aromatic hydrocarbon group, and a phosphate having an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: May 11, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideharu Takezawa, Yasuhiko Bito, Hiromu Matsuda, Yoshinori Toyoguchi
  • Publication number: 20040062982
    Abstract: An electrode group for a battery including a positive electrode and a negative electrode wound into a spiral with a separator interposed therebetween, wherein the positive electrode includes a positive electrode current collector and positive electrode material mixture layers formed on both sides of the positive electrode current collector, the negative electrode includes a negative electrode current collector and negative electrode material mixture layers formed on both sides of the negative electrode current collector, a lead is connected to at least one of the positive electrode current collector and the negative electrode current collector, and at least one of step portions having difference in level formed in the electrode group by lengthwise ends of the positive electrode, the negative electrode and the separator and the periphery of the lead, respectively, is covered with an insulating member arranged on an inner circumference side or an outer circumference side of a turn of the electrode group.
    Type: Application
    Filed: September 22, 2003
    Publication date: April 1, 2004
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Hideharu Takezawa, Shuji Tsutsumi, Mikinari Shimada