Patents by Inventor Yasuhiro Wakizaka

Yasuhiro Wakizaka 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: 8877376
    Abstract: A secondary battery electrode which suppresses decrease in capacity and lithium deposition at low temperatures is provided. An electrode for a secondary battery includes an electrode active material layer containing a polymer having a cationic group, an anion corresponding to the cationic group, and an electrode active material, and the cation density in the polymer is 0.1 to 15 meq/g.
    Type: Grant
    Filed: June 30, 2010
    Date of Patent: November 4, 2014
    Assignee: ZEON Corporation
    Inventors: Yasuhiro Wakizaka, Kei Kobayashi, Toshiyuki Sekine
  • Patent number: 8852788
    Abstract: Disclosed is a porous membrane used for a secondary battery, such as lithium-ion secondary battery, wherein strength is improved and break is difficult to occur while maintaining lithium-ion conductivity. The porous membrane for a secondary battery comprising a binder for the porous membrane and a nonconductive particle, wherein the binder for the porous membrane is a polymer particle having a hetero phase structure, in which internal layer is a polymer wherein vinyl monomer components are polymerized and outer layer is a polymer wherein monomer components containing a hydrophilic functional group are polymerized. The hydrophilic functional group is at least one selected from the group consisting sulfonic acid group, carboxyl group, hydroxyl group and epoxy group.
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: October 7, 2014
    Assignee: Zeon Corporation
    Inventors: Yasuhiro Wakizaka, Nobukazu Kaihatsu
  • Patent number: 8841024
    Abstract: A secondary battery electrode which suppresses decrease in capacity and lithium deposition at low temperatures is provided. An electrode for a secondary battery includes an electrode active material layer containing a polymer having a cationic group, an anion corresponding to the cationic group, and an electrode active material, and the cation density in the polymer is 0.1 to 15 meq/g.
    Type: Grant
    Filed: June 30, 2010
    Date of Patent: September 23, 2014
    Assignee: ZEON Corporation
    Inventors: Yasuhiro Wakizaka, Kei Kobayashi, Toshiyuki Sekine
  • Patent number: 8822074
    Abstract: Disclosed is an electrode for a lithium-ion secondary battery which includes a porous membrane layer that is inhibited from decreasing in flexibility. The electrode for lithium-ion secondary battery comprises a current collector and, formed thereon in the following order, an electrode active-material layer comprising an electrode active material, a thickener, and a binder and a porous membrane layer containing an inorganic filler, wherein the binder is one which, when used to form a composite film comprising the binder and the thickener, forms a spherical island phase in a cross section of the composite film, the island phase having an average diameter of 0.5 ?m or larger. The binder preferably is an unsaturated carboxylic acid ester polymer having a content of alkyl acrylate monomer units of 85 mass % or higher.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: September 2, 2014
    Assignee: Zeon Corporation
    Inventors: Yasuhiro Wakizaka, Takumi Sugimoto
  • Publication number: 20140023922
    Abstract: Disclosed is a manufacturing method of an electrode for an electrochemical element having a superior adhesion and is used for an electrochemical element with excellent productivity due to a short predoping time. Specifically disclosed is that the method is characterized by comprising a step for compression forming of electrode material (a mixed powder or composite particles) including an alkaline metal powder or an alkaline earth metal powder each having a coated surface.
    Type: Application
    Filed: January 23, 2012
    Publication date: January 23, 2014
    Applicant: ZEON CORPORATION
    Inventors: Yasuhiro Isshiki, Yasuhiro Wakizaka
  • Publication number: 20130273421
    Abstract: A secondary battery porous membrane, manufactured by a slurry for secondary battery porous membrane, which is superior in coating priority and dispersibility of non-conductive organic particles, which improves cycle characteristic of the obtained secondary battery, which has high flexibility and can prevent powder falls, and which has less content of moisture amount; and non-conductive organic particles, which can be suitably used as a secondary battery porous membrane and has less content of metallic foreign particles. The slurry for secondary battery porous membrane comprises; a binder including a polymerized unit of vinyl monomer having a hydrophilic acid group, a non-conductive organic particle having a functional group, cross-linkable with the hydrophilic acid group and a solvent.
    Type: Application
    Filed: October 7, 2011
    Publication date: October 17, 2013
    Applicant: ZEON CORPORATION
    Inventors: Taku Matsumura, Takuya Kaneda, Yasuhiro Wakizaka
  • Publication number: 20130230768
    Abstract: A binder composition for a non-aqueous battery electrode containing a binder and an ether compound represented by the formula (1), and an electrolyte solution composition for a non-aqueous battery containing an ether compound represented by the formula (1), wherein m and n each independently represent 0 or 1, and R1 represents a divalent linear hydrocarbon group which may have in the bond thereof one or more intervening groups selected from the group consisting of an oxygen atom, a sulfur atom, and a carbonyl group.
    Type: Application
    Filed: June 28, 2011
    Publication date: September 5, 2013
    Applicant: ZEON CORPORATION
    Inventors: Kei Sakamoto, Natsuko Nakata, Yasuhiro Wakizaka
  • Patent number: 8426062
    Abstract: Disclosed is a binder composition for a nonaqueous electrolyte secondary battery electrode including an antioxidizing agent, able to inhibit the thickening of an electrode slurry. The binder composition enables to form electrode slurry without making the antioxidizing agent adhere to the insides of fine pores of electrode active materials after coating and drying. The binder composition for a nonaqueous electrolyte secondary battery electrode contains a binder and an emulsified antioxidizing agent, and particularly, it is preferable that the binder is an aqueous binder including a diene-based polymer and that the antioxidizing agent is a polymeric phenol compound.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: April 23, 2013
    Assignee: Zeon Corporation
    Inventors: Yasuhiro Wakizaka, Kei Kobayashi
  • Patent number: 8349490
    Abstract: The present invention is directed to an electrode for a nonaqueous electrolyte secondary battery and a nonaqueous electrolyte secondary battery using the same. The nonaqueous electrolyte secondary battery electrode includes an electrode material mixture and a current collector. The electrode material mixture includes an active material and a polymer. The thickness change rate of the electrode material mixture is ?3 to 10% when immersing in an electrolyte at 60° C. for 72 hours.
    Type: Grant
    Filed: September 11, 2007
    Date of Patent: January 8, 2013
    Assignee: Zeon Corporation
    Inventors: Fumio Takano, Yasuhiro Wakizaka
  • Patent number: 8277977
    Abstract: The present invention aims at providing slurry for electrodes having advantageous homogeneity and stability, an electrode having advantageous homogeneous thickness and density, and further, a nonaqueous electrolyte secondary battery having small variability in battery properties. In the present invention, slurry for electrodes is produced by using the binder composition used for manufacturing a nonaqueous electrolyte secondary battery wherein polymers for binding active materials are dissolved or dispersed in organic solvent or water, and a total sum of content ratios of monomer and oligomer is 300 ppm or less.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: October 2, 2012
    Assignee: Zeon Corporation
    Inventors: Fumiaki Tsuchiya, Yasuhiro Wakizaka
  • Publication number: 20120189898
    Abstract: Disclosed is a porous membrane used for a secondary battery, such as lithium-ion secondary battery, wherein strength is improved and break is difficult to occur while maintaining lithium-ion conductivity. The porous membrane for a secondary battery comprising a binder for the porous membrane and a nonconductive particle, wherein the binder for the porous membrane is a polymer particle having a hetero phase structure, in which internal layer is a polymer wherein vinyl monomer components are polymerized and outer layer is a polymer wherein monomer components containing a hydrophilic functional group are polymerized. The hydrophilic functional group is at least one selected from the group consisting sulfonic acid group, carboxyl group, hydroxyl group and epoxy group.
    Type: Application
    Filed: September 29, 2010
    Publication date: July 26, 2012
    Applicant: Zeon Corporation
    Inventors: Yasuhiro Wakizaka, Nobukazu Kaihatsu
  • Publication number: 20120189897
    Abstract: Disclosed is a porous membrane for a secondary battery, which has further improved output characteristics and long-term cycle characteristics when compared with conventional porous membranes. The porous membrane for a secondary battery is used for a lithium ion secondary battery or the like. Specifically disclosed is a porous membrane for a secondary battery, which contains polymer particles A that have a number average particle diameter of 0.4 ?m or more but less than 10 ?m and a glass transition temperature of 65° C. or more and polymer particles B that have a number average particle diameter of 0.04 ?m or more but less than 0.3 ?m and a glass transition temperature of 15° C. or less. It is preferable that the polymer particles B have a crystallization degree of 40% or less and a main chain structure that is composed of a saturated structure.
    Type: Application
    Filed: September 30, 2010
    Publication date: July 26, 2012
    Inventors: Yasuhiro Wakizaka, Naoki Yoshida
  • Publication number: 20120189913
    Abstract: A negative electrode for a lithium ion secondary battery including an active material layer that is disposed on a current collector and that contains a negative electrode active material and a binder, in which the negative electrode active material includes an alloy active material and a carbon active material, and the weight ratio between the alloy active material and the carbon active material in the active material layer is 20:80 to 50:50, and the binder contains 0.1 to 15 wt % of an ethylenically unsaturated carboxylic acid monomer polymerization unit.
    Type: Application
    Filed: September 22, 2010
    Publication date: July 26, 2012
    Inventors: Yasuhiro Wakizaka, Kei Kobayashi
  • Publication number: 20120107690
    Abstract: A secondary battery electrode which suppresses decrease in capacity and lithium deposition at low temperatures is provided. An electrode for a secondary battery includes an electrode active material layer containing a polymer having a cationic group, an anion corresponding to the cationic group, and an electrode active material, and the cation density in the polymer is 0.1 to 15 meq/g.
    Type: Application
    Filed: June 30, 2010
    Publication date: May 3, 2012
    Applicant: ZEON CORPORATION
    Inventors: Yasuhiro Wakizaka, Kei Kobayashi, Toshiyuki Sekine
  • Publication number: 20110318630
    Abstract: The invention intends to provide a separator for lithium ion secondary battery wherein the separator with porous film used for lithium ion secondary battery include binder, which is capable to contribute for improving film smoothness property of the separator and long term cycle property. The invention provides a separator for lithium ion secondary battery characterized in that; porous film including nonconductive particles and binder is laminated on organic separator, and said binder includes copolymer comprising monomer unit derived from (meth)acrylonitrile monomer unit and monomer unit derived from (meth)acrylic ester, and a lithium ion secondary battery comprising; a positive electrode, a negative electrode, an electrolyte solution, and said separator.
    Type: Application
    Filed: December 25, 2009
    Publication date: December 29, 2011
    Applicant: ZEON CORPORATION
    Inventors: Yasuhiro Wakizaka, Mayumi Fukumine
  • Publication number: 20110311870
    Abstract: Disclosed is an electrode for a lithium-ion secondary battery which includes a porous membrane layer that is inhibited from decreasing in flexibility. The electrode for lithium-ion secondary battery comprises a current collector and, formed thereon in the following order, an electrode active-material layer comprising an electrode active material, a thickener, and a binder and a porous membrane layer containing an inorganic filler, wherein the binder is one which, when used to form a composite film comprising the binder and the thickener, forms a spherical island phase in a cross section of the composite film, the island phase having an average diameter of 0.5 ?m or larger. The binder preferably is an unsaturated carboxylic acid ester polymer having a content of alkyl acrylate monomer units of 85 mass % or higher.
    Type: Application
    Filed: February 26, 2010
    Publication date: December 22, 2011
    Inventors: Yasuhiro Wakizaka, Takumi Sugimoto
  • Publication number: 20110311867
    Abstract: Disclosed is a negative electrode active material for a lithium ion secondary battery, which is capable of further improving the charge/discharge cycle characteristics. Also disclosed is a lithium ion secondary battery which uses the negative electrode active material for a lithium ion secondary battery. The negative electrode active material for a lithium ion secondary battery is composed of composite particles each of which has a core/shell structure configured of a core part that is formed from a polymer and a shell part that is formed of a metal layer. The metal layer of the shell part is formed by metal plating. Preferably, the metal layer comprises at least a metal layer (a1) that is formed by electroless plating and a metal layer (a2) that is formed by electrolytic plating, in this order from the core part side.
    Type: Application
    Filed: February 26, 2010
    Publication date: December 22, 2011
    Inventors: Yasuhiro Wakizaka, Takumi Sugimoto
  • Publication number: 20110171526
    Abstract: A binder composition for secondary batteries having excellent stability over time is produced. A method for producing a binder composition for secondary batteries containing at least a polymer and a dispersion medium, which comprises a metal particulate removal step wherein metal particulates contained in a polymer dispersion containing a polymer and a dispersion medium are removed. A binder composition for secondary batteries, which is obtained by the above-mentioned production method and has a metal particulate content of not more than 10 ppm, said metal particulate content is composed of particles formed from a transition metal component and having a particle diameter of not less than 20 ?m. A slurry for secondary battery electrodes, which contains the binder composition for secondary batteries and an electrode active material.
    Type: Application
    Filed: September 17, 2009
    Publication date: July 14, 2011
    Inventors: Yasuhiro Wakizaka, Yosuke Yabuuchi
  • Publication number: 20110129731
    Abstract: Disclosed is an electrode for a lithium-ion secondary battery in which a porous membrane containing an oxide particle having a particle size of 5 nm or more to 100 nm or less is layered on an electrode active material layer; a slurry for a porous membrane comprising an oxide particle having a particle size of 5 nm or more to 100 nm or less, a polymer having a glass-transition temperature of 15° C. or less and a solvent; and a lithium-ion secondary battery comprising a positive electrode, a negative electrode and an electrolyte solution in which at least one of the positive electrode and negative electrode is the electrode of the present invention. The purpose is to provide a porous membrane able to contribute to reduction of an attached matter to a roll when being wound up due to improved retention of inorganic filler on the surface part of the porous membrane for a porous protective membrane provided on the surface of an electrode used for a secondary battery and the like.
    Type: Application
    Filed: August 4, 2009
    Publication date: June 2, 2011
    Inventors: Yasuhiro Wakizaka, Mayumi Fukumine
  • Publication number: 20110091774
    Abstract: Provided is a porous film that can contribute to improving the cycle characteristics of an electric cell by improving binding characteristics, for a porous film provided on a surface of an electrode used in a secondary cell and the like. The porous film comprises a water-soluble polymer, an inorganic filler, and a water-insoluble particulate polymer including 0.5-40 mass % of a monomer unit having a hydrophilic group selected from the group consisting of carboxylic acid groups, hydroxyl groups, and sulfonate groups.
    Type: Application
    Filed: March 31, 2009
    Publication date: April 21, 2011
    Applicant: ZEON CORPORATION
    Inventors: Yasuhiro Wakizaka, Mayumi Fukumi