Patents by Inventor Shouichiro Sawa

Shouichiro Sawa 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: 20240030438
    Abstract: A non-aqueous electrolyte secondary battery positive electrode that is characterized by comprising a positive electrode collector and a positive electrode mixture layer that is provided on the positive electrode collector and includes a positive electrode active material and a conductive material that includes carbon nanotubes. The non-aqueous electrolyte secondary battery positive electrode is also characterized in that, when the positive electrode mixture layer is bisected in the thickness direction, the mass ratio of carbon nanotubes to positive electrode active material in an upper-half region that is on a top surface side is smaller than the mass ratio of carbon nanotubes to positive electrode active material in a lower-half region that is on the positive electrode collector side.
    Type: Application
    Filed: November 25, 2021
    Publication date: January 25, 2024
    Applicant: Panasonic Energy Co., Ltd
    Inventors: Masahiro Kinoshita, Shouichiro Sawa, Koki Morita, Tomoki Ikeda
  • Patent number: 10109856
    Abstract: A negative electrode including a current collector, a first mix layer containing first active material particles and a binder, and a second mix layer containing second active material particles and a binder. The first mix layer is placed on the current collector. The second mix layer overlies the first mix layer. The first active material particles and the second active material particles contain Si. The second mix layer includes a plurality of pillar portions. The expansion coefficient of the second mix layer during charge is higher than the expansion coefficient of the first mix layer during charge. The electrical conductivity of the first mix layer is higher than the electrical conductivity of the second mix layer.
    Type: Grant
    Filed: September 18, 2014
    Date of Patent: October 23, 2018
    Assignee: SANYO Electric Co., Ltd.
    Inventor: Shouichiro Sawa
  • Patent number: 9711783
    Abstract: A negative electrode for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode mixture layer that contains a binder and a negative electrode active material particle that forms an alloy with lithium and is formed on a current collector. The negative electrode mixture layer includes a base portion near the current collector and pillar-shaped portions formed on the base portion. A negative electrode for a nonaqueous electrolyte secondary battery according to another aspect of the present invention includes a negative electrode mixture layer that contains a binder and a negative electrode active material particle that forms an alloy with lithium and is formed on a current collector. The negative electrode mixture layer includes pillar-shaped portions and the particle diameter of the negative electrode active material particle is 20% or less of the maximum diameter of the pillar-shaped portions.
    Type: Grant
    Filed: January 10, 2014
    Date of Patent: July 18, 2017
    Assignees: SANYO Electric Co., Ltd., PANASONIC Corporation
    Inventors: Kazuto Fukuda, Ayano Toyoda, Shouichiro Sawa, Taizou Sunano
  • Patent number: 9705135
    Abstract: There are provided a negative electrode for a nonaqueous electrolyte secondary battery having excellent initial efficiency and good moldability of pillar portions included in a negative electrode mixture layer, and a nonaqueous electrolyte secondary battery. A negative electrode (20) for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode current collector (21) and a negative electrode mixture layer (22) formed on the negative electrode current collector (21) and containing a binder and a negative electrode active material particle that forms an alloy with lithium. The negative electrode mixture layer (22) includes a base portion (22a) near the negative electrode current collector (21) and pillar portions (22b) formed on the base portion (21a). The binder contains a polyimide resin. The polyimide resin has an average molecular weight of 60000 or more.
    Type: Grant
    Filed: March 19, 2014
    Date of Patent: July 11, 2017
    Assignee: SANYO Electric Co., Ltd.
    Inventors: Shouichiro Sawa, Ayano Toyoda, Taizou Sunano
  • Publication number: 20160204431
    Abstract: A negative electrode including a current collector, a first mix layer containing first active material particles and a binder, and a second mix layer containing second active material particles and a binder. The first mix layer is placed on the current collector. The second mix layer overlies the first mix layer. The first active material particles and the second active material particles contain Si. The second mix layer includes a plurality of pillar portions. The expansion coefficient of the second mix layer during charge is higher than the expansion coefficient of the first mix layer during charge. The electrical conductivity of the first mix layer is higher than the electrical conductivity of the second mix layer.
    Type: Application
    Filed: September 18, 2014
    Publication date: July 14, 2016
    Applicant: SANYO Electric Co., Ltd.
    Inventor: Shouichiro Sawa
  • Publication number: 20160056475
    Abstract: There are provided a negative electrode for a nonaqueous electrolyte secondary battery having excellent initial efficiency and good moldability of pillar portions included in a negative electrode mixture layer, and a nonaqueous electrolyte secondary battery. A negative electrode (20) for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode current collector (21) and a negative electrode mixture layer (22) formed on the negative electrode current collector (21) and containing a binder and a negative electrode active material particle that forms an alloy with lithium. The negative electrode mixture layer (22) includes a base portion (22a) near the negative electrode current collector (21) and pillar portions (22b) formed on the base portion (21a). The binder contains a polyimide resin. The polyimide resin has an average molecular weight of 60000 or more.
    Type: Application
    Filed: March 19, 2014
    Publication date: February 25, 2016
    Applicant: SANYO Electric Co., Ltd.
    Inventors: Shouichiro Sawa, Ayano Toyoda, Taizou Sunano
  • Publication number: 20160049651
    Abstract: A nonaqueous electrolyte secondary battery which has a good capacity retention ratio (cycle characteristics) and in which the expansion and shrinkage during charging and discharging are small compared with the case where a negative electrode made of only a negative electrode active material that forms an alloy with lithium is used. A negative electrode for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode mixture layer formed on a current collector and containing a binder and a negative electrode active material particle that forms an alloy with lithium. The negative electrode mixture layer includes pillar portions, and a value of S1/S2 is 0.46 or more and 0.58 or less, where S1 represents a total area of the pillar portions in plan view and S2 represents a total area of one surface of the negative electrode current collector in plan view.
    Type: Application
    Filed: March 18, 2014
    Publication date: February 18, 2016
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Shouichiro Sawa, Ayano Toyoda, Taizou Sunano
  • Publication number: 20150364752
    Abstract: A negative electrode for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode mixture layer that contains a binder and a negative electrode active material particle that forms an alloy with lithium and is formed on a current collector. The negative electrode mixture layer includes a base portion near the current collector and pillar-shaped portions formed on the base portion. A negative electrode for a nonaqueous electrolyte secondary battery according to another aspect of the present invention includes a negative electrode mixture layer that contains a binder and a negative electrode active material particle that forms an alloy with lithium and is formed on a current collector. The negative electrode mixture layer includes pillar-shaped portions and the particle diameter of the negative electrode active material particle is 20% or less of the maximum diameter of the pillar-shaped portions.
    Type: Application
    Filed: January 10, 2014
    Publication date: December 17, 2015
    Applicants: SANYO ELECTRIC CO., LTD., PANASONIC CORPORATION
    Inventors: Kazuto Fukuda, Ayano Toyoda, Shouichiro Sawa, Taizou Sunano
  • Patent number: 9070940
    Abstract: A lithium secondary battery with superior cycle performance is provided. The lithium secondary battery includes a negative electrode including a negative electrode active material layer disposed on a negative electrode current collector and containing negative electrode active material particles, negative electrode conductor particles, and a negative electrode binder; a positive electrode containing a positive electrode active material; and a non-aqueous electrolyte. The concentration of the negative electrode conductor particles in a surface layer of the negative electrode active material layer facing away from the negative electrode current collector is higher than the concentration of the negative electrode conductor particles in a center of the negative electrode active material layer.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: June 30, 2015
    Assignee: SANYO Electric Co., Ltd.
    Inventors: Shouichiro Sawa, Atsushi Fukui, Taizou Sunano
  • Patent number: 9048502
    Abstract: A lithium secondary battery and a method for producing the lithium secondary battery. The lithium secondary battery includes a negative electrode 1 in which negative electrode mixture layers 2 and 3 that contain active material particles containing silicon and/or a silicon alloy and a binder are disposed on the surfaces of a current collector 4. A electrode body is formed by spirally winding, from inside to outside, a laminate body; and in an outer end portion of the negative electrode 1, the negative electrode mixture layers 2 and 3 have tapering portions 2a and 3a whose thicknesses decrease toward ends 2b and 3b of the negative electrode mixture layers 2 and 3; and oozing portions 2d and 3d mainly containing the binder are formed at the tips of the tapering portions 2a and 3a of the negative electrode mixture layers 2 and 3.
    Type: Grant
    Filed: December 7, 2011
    Date of Patent: June 2, 2015
    Assignee: SANYO Electric Co., Ltd.
    Inventors: Shouichiro Sawa, Atsushi Fukui, Yasunori Watanabe, Taizou Sunano
  • Publication number: 20140004415
    Abstract: A lithium secondary battery with superior cycle performance is provided. The lithium secondary battery includes a negative electrode including a negative electrode active material layer disposed on a negative electrode current collector and containing negative electrode active material particles, negative electrode conductor particles, and a negative electrode hinder; a positive electrode containing a positive electrode active material; and a non-aqueous electrolyte. The concentration of the negative electrode conductor particles in a surface layer of the negative electrode active material layer facing away from the negative electrode current collector is higher than the concentration of the negative electrode conductor particles in a center of the negative electrode active material layer.
    Type: Application
    Filed: March 16, 2012
    Publication date: January 2, 2014
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Shouichiro Sawa, Atsushi Fukui, Taizou Sunano
  • Publication number: 20130266834
    Abstract: A lithium secondary battery and a method for producing the lithium secondary battery. The lithium secondary battery includes a negative electrode 1 in which negative electrode mixture layers 2 and 3 that contain active material particles containing silicon and/or a silicon alloy and a binder are disposed on the surfaces of a current collector 4. A electrode body is formed by spirally winding, from inside to outside, a laminate body; and in an outer end portion of the negative electrode 1, the negative electrode mixture layers 2 and 3 have tapering portions 2a and 3a whose thicknesses decrease toward ends 2b and 3b of the negative electrode mixture layers 2 and 3; and oozing portions 2d and 3d mainly containing the binder are formed at the tips of the tapering portions 2a and 3a of the negative electrode mixture layers 2 and 3.
    Type: Application
    Filed: December 7, 2011
    Publication date: October 10, 2013
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Shouichiro Sawa, Atsushi Fukui, Yasunori Watanabe, Taizou Sunano
  • Patent number: 8101295
    Abstract: A lithium secondary battery has a wound electrode assembly (5). The wound electrode assembly (5) has a negative electrode (2) having a negative electrode active material layer containing a negative electrode active material capable of alloying with lithium and having a filling density of 2.0 g/cc or less, a positive electrode (1) having a positive electrode active material layer containing a positive electrode active material made of a transition metal composite oxide, a separator (3) disposed between the positive and negative electrodes and having a penetration resistance of 500 g or greater, and a cylindrical hollow space (14) at a winding axis and in the vicinity thereof, wherein the positive electrode (1), the negative electrode (2), and the separator (3) are spirally wound. A columnar center pin (15) having a diameter of from 75% to 95% of the diameter of the hollow space is disposed in the hollow space.
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: January 24, 2012
    Assignee: SANYO Electric Co., Ltd.
    Inventors: Shouichiro Sawa, Taizou Sunano, Maruo Kamino
  • Publication number: 20080286654
    Abstract: A non-aqueous electrolyte secondary battery is composed of a positive electrode, a negative electrode, and a non-aqueous electrolyte, and the negative electrode has a negative electrode composite layer containing a negative electrode active material and a binder formed on a negative electrode current collector. The negative electrode active material contains a complex alloy powder containing tin, cobalt and carbon and graphite powder, and the negative electrode composite layer formed on the negative electrode current collector has percentage of porosity within the range of 5 to 20 volume %.
    Type: Application
    Filed: May 13, 2008
    Publication date: November 20, 2008
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Shouichiro Sawa, Mariko Torimae, Yasuyuki Kusumoto, Hiroyuki Fujimoto
  • Publication number: 20080241646
    Abstract: A lithium secondary battery has a wound electrode assembly (5). The wound electrode assembly (5) has a negative electrode (2) having a negative electrode active material layer containing a negative electrode active material capable of alloying with lithium and having a filling density of 2.0 g/cc or less, a positive electrode (1) having a positive electrode active material layer containing a positive electrode active material made of a transition metal composite oxide, a separator (3) disposed between the positive and negative electrodes and having a penetration resistance of 500 g or greater, and a cylindrical hollow space (14) at a winding axis and in the vicinity thereof, wherein the positive electrode (1), the negative electrode (2), and the separator (3) are spirally wound. A columnar center pin (15) having a diameter of from 75% to 95% of the diameter of the hollow space is disposed in the hollow space.
    Type: Application
    Filed: March 27, 2008
    Publication date: October 2, 2008
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Shouichiro Sawa, Taizou Sunano, Maruo Kamino