Patents by Inventor Taro Yamafuku

Taro Yamafuku 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: 20210399347
    Abstract: Provided is a method for manufacturing an energy storage device including an electrode that has an active material layer, an electrolyte solution, and a case. According to the present embodiment, the method including injecting an electrolyte solution in a predetermined amount into a case is characterized in that the predetermined amount is an amount such that, an alkali metal or an alkaline earth metal at least partially comes into contact with a free electrolyte solution that is the electrolyte solution excluding the electrolyte solution soaking into the electrode assembly in the case, with the case housing therein: the alkali metal or the alkaline earth metal of an ion supply member that has the alkali metal or the alkaline earth metal disposed on a conductive member other than the active material layer; and an electrode assembly including the stacked electrode that has electrical conduction to the conducive member of the ion supply member.
    Type: Application
    Filed: September 26, 2019
    Publication date: December 23, 2021
    Inventors: Taro YAMAFUKU, Kenta NAKAI, Jun OYAMA
  • Publication number: 20210257618
    Abstract: An aspect of the present invention is an energy storage device including an electrode assembly that has a negative electrode and a positive electrode, where the negative electrode contains a negative electrode substrate and a negative active material, and has a negative active material layer disposed in an unpressed shape along at least one surface of the negative electrode substrate, the negative active material includes solid graphite particles as a main component, and the solid graphite particles have an aspect ratio of 1 or more and 5 or less.
    Type: Application
    Filed: September 10, 2019
    Publication date: August 19, 2021
    Inventors: Kenta OGI, Fumiya NAKANO, Ryosuke SHIMOKAWA, Shota ITO, Masaki MASUDA, Taro YAMAFUKU, Kei KUMABAYASHI, Akihiko MIYAZAKI
  • Patent number: 10991969
    Abstract: An energy storage device includes: a flattened electrode assembly formed by winding electrodes such that a hollow portion is formed, the electrode assembly including a pair of curved portions opposed manner in a major axis direction and a pair of flat portions opposed in a minor axis direction; and a case storing the electrode assembly therein, wherein assuming a thickness of the flat portion in the minor axis direction as A, a thickness of the curved portion in a radial direction as B, and a thickness of the hollow portion in the minor axis direction as W, the electrode assembly satisfies A+(W/2)?B in a state where the electrode assembly is discharged.
    Type: Grant
    Filed: August 12, 2015
    Date of Patent: April 27, 2021
    Assignee: GS Yuasa International Ltd.
    Inventors: Takeshi Sasaki, Taro Yamafuku, Masaki Masuda
  • Patent number: 10634729
    Abstract: According to an embodiment of the present invention, deterioration of a non-aqueous electrolyte power storage element is detected based on a first increase rate and a second increase rate, the first increase rate being an increase rate of a direct current resistance value obtained by measuring the non-aqueous electrolyte power storage element over a first time period, the second increase rate being an increase rate of a direct current resistance value obtained by measuring the non-aqueous electrolyte power storage element over a second time period that is longer than the first time period.
    Type: Grant
    Filed: March 14, 2016
    Date of Patent: April 28, 2020
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Taro Yamafuku, Masaki Masuda, Kazuki Kawaguchi, Masashi Takano
  • Patent number: 10340482
    Abstract: An energy storage apparatus includes: at least one energy storage device which includes an electrode assembly and a case for housing the electrode assembly; a spacer which is arranged adjacent to the case; and a holder which holds the energy storage device and the spacer. The energy storage device includes an insulating film which covers an outer surface of the case and is adhered to at least a portion of the outer surface of the case. The spacer has at least one of edges and corners thereof disposed at positions where the edges or the corners are in contact with the outer surface of the case with the insulating film interposed therebetween.
    Type: Grant
    Filed: September 9, 2015
    Date of Patent: July 2, 2019
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Taro Yamafuku, Takeshi Sasaki
  • Patent number: 10319957
    Abstract: An energy storage device includes a metal case which houses an electrode assembly therein, and an insulation sheet mounted on a portion of an outer surface of the case. The case includes a projecting portion which extends in a thickness direction of the insulation sheet along an edge surface of at least a portion of the insulation sheet, and a distal end of the projecting portion projects from the insulation sheet.
    Type: Grant
    Filed: September 21, 2016
    Date of Patent: June 11, 2019
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Taro Yamafuku, Masaki Masuda
  • Patent number: 10003061
    Abstract: An energy storage device includes: an electrode assembly; a case for storing the electrode assembly therein, the case having an electrolyte solution sealing portion where an electrolyte solution pouring hole formed in the case is sealed; and at least one partition member arranged in a gap formed between the case and the electrode assembly stored in the case. The partition member partitions the gap in the winding axis direction of the electrode assembly by surrounding the electrode assembly in the winding direction of the electrode. The electrolyte solution pouring hole is arranged at a position closer to one end of the electrode assembly than the partition member close to one end of the case is in the winding axis direction.
    Type: Grant
    Filed: June 4, 2015
    Date of Patent: June 19, 2018
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Taro Yamafuku, Sumio Mori
  • Patent number: 9991563
    Abstract: An energy storage device includes a positive electrode and a negative electrode. The negative electrode includes graphite and non-graphitizable carbon, and a D50 particle size of the graphite at which a cumulative volume in a particle size distribution of a particle size reaches 50% is 2 ?m or more. A ratio of a mass of the non-graphitizable carbon to a total amount of a mass of the graphite and a mass of the non-graphitizable carbon is 5% by mass or more and 45% by mass or less and a ratio of the D50 particle size of the graphite to a D50 particle size of the non-graphitizable carbon is 1.02 or less.
    Type: Grant
    Filed: May 26, 2016
    Date of Patent: June 5, 2018
    Assignee: GS Yuasa International Ltd.
    Inventors: Tomonori Kako, Taro Yamafuku, Akihiko Miyazaki
  • Patent number: 9960406
    Abstract: An energy storage device includes: a first guide portion which is arranged in the inside of a case and allows an electrolyte solution to flow toward one end of an electrode assembly in a winding axis direction from an electrolyte solution pouring hole; and a second guide portion which is arranged in the inside of the case and allows a fluid to flow toward the electrolyte solution pouring hole from the inside of the case, and which prevents the electrolyte solution from flowing toward the other end of the electrode assembly in the winding axis direction from the electrolyte solution pouring hole or suppresses the electrolyte solution from flowing toward the other end of the electrode assembly in the winding axis direction from the electrolyte solution pouring hole.
    Type: Grant
    Filed: June 6, 2015
    Date of Patent: May 1, 2018
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Taro Yamafuku, Kazuki Kawaguchi, Masaki Masuda, Masashi Takano
  • Patent number: 9954219
    Abstract: Provided is an electric storage device including: a first electrode plate, a second electrode plate having a polarity opposite to that of the first electrode plate, and a separator interposed between the first electrode plate and the second electrode plate, wherein the first electrode plate includes a current collector, a conductive layer laminated onto the current collector, and a mixture layer laminated onto the conductive layer, the mixture layer contains a binder and primary particles of an active material as its constituents, and the primary particles as a constituent of the mixture layer are partially retained in the conductive layer.
    Type: Grant
    Filed: January 10, 2014
    Date of Patent: April 24, 2018
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Taro Yamafuku, Masaki Masuda, Kazuki Kawaguchi, Takeshi Sasaki
  • Publication number: 20180080996
    Abstract: According to an embodiment of the present invention, deterioration of a non-aqueous electrolyte power storage element is detected based on a first increase rate and a second increase rate, the first increase rate being an increase rate of a direct current resistance value obtained by measuring the non-aqueous electrolyte power storage element over a first time period, the second increase rate being an increase rate of a direct current resistance value obtained by measuring the non-aqueous electrolyte power storage element over a second time period that is longer than the first time period.
    Type: Application
    Filed: March 14, 2016
    Publication date: March 22, 2018
    Inventors: Taro YAMAFUKU, Masaki MASUDA, Kazuki KAWAGUCHI, Masashi TAKANO
  • Patent number: 9905827
    Abstract: An energy storage apparatus includes: an energy storage device including a flat electrode assembly in which electrodes are layered and a prismatic case in which the electrode assembly is housed; and a spacer arranged adjacently to the energy storage device in a first direction, wherein the spacer is formed such that a thickness size in the first direction of a center portion of the spacer in a second direction, which is a direction orthogonal to the first direction and is a direction parallel to a surface of the spacer that faces the energy storage device, is set larger than a thickness size in the first direction of other portions of the spacer arranged adjacently to the center portion of the spacer in the second direction, and a width of the center portion of the spacer in a third direction orthogonal to the first and second directions at a contact portion of the spacer with the energy storage device is set smaller than a width of the case in the third direction.
    Type: Grant
    Filed: November 30, 2015
    Date of Patent: February 27, 2018
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Taro Yamafuku, Takeshi Sasaki
  • Patent number: 9660251
    Abstract: Provided is an electric storage device including: a first electrode plate; a second electrode plate having a polarity opposite to that of the first electrode plate; and a separator interposed between the first electrode plate and the second electrode plate, wherein the first electrode plate includes a current collector and a mixture layer laminated onto the current collector, the mixture layer contains at least one of the binder and the conductive additive, primary particles of an active material, and secondary particles each having a hollow region formed therein by aggregation of a plurality of the primary particles, and the at least one of the binder and the conductive additive is partially distributed in the hollow region.
    Type: Grant
    Filed: January 10, 2014
    Date of Patent: May 23, 2017
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Takeshi Sasaki, Taro Yamafuku, Kazuki Kawaguchi, Masaki Masuda
  • Publication number: 20170092901
    Abstract: An energy storage device includes a metal case which houses an electrode assembly therein, and an insulation sheet mounted on a portion of an outer surface of the case. The case includes a projecting portion which extends in a thickness direction of the insulation sheet along an edge surface of at least a portion of the insulation sheet, and a distal end of the projecting portion projects from the insulation sheet.
    Type: Application
    Filed: September 21, 2016
    Publication date: March 30, 2017
    Inventors: Taro YAMAFUKU, Masaki MASUDA
  • Publication number: 20160351967
    Abstract: An energy storage device includes a positive electrode and a negative electrode. The negative electrode includes graphite and non-graphitizable carbon, and a D50 particle size of the graphite at which a cumulative volume in a particle size distribution of a particle size reaches 50% is 2 ?m or more. A ratio of a mass of the non-graphitizable carbon to a total amount of a mass of the graphite and a mass of the non-graphitizable carbon is 5% by mass or more and 45% by mass or less and a ratio of the D50 particle size of the graphite to a D50 particle size of the non-graphitizable carbon is 1.02 or less.
    Type: Application
    Filed: May 26, 2016
    Publication date: December 1, 2016
    Inventors: Tomonori KAKO, Taro YAMAFUKU, Akihiko MIYAZAKI
  • Patent number: 9472798
    Abstract: An energy storage device includes a casing, a power generating element, a current collector, a connection conductor, an external terminal, and a rivet. The energy storage device further includes a welded portion where at least one of a contact portion between a casing inner portion of the rivet and the current collector, a contact portion between a casing outer portion of the rivet and the connection conductor, and a contact portion between the connection conductor and the external terminal is welded at least partially.
    Type: Grant
    Filed: April 16, 2013
    Date of Patent: October 18, 2016
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Masaki Masuda, Taro Yamafuku
  • Publication number: 20160285074
    Abstract: An energy storage device includes an electrode having an electrode substrate; an active material layer which is disposed to cover a surface of the electrode substrate and which contains active material particles; and an intermediate layer which is disposed between the electrode substrate and the active material layer and which contains a binder, wherein the active material particles of the active material layer enter the intermediate layer, and are in contact with the electrode substrate and the intermediate layer.
    Type: Application
    Filed: March 23, 2016
    Publication date: September 29, 2016
    Inventors: Taro YAMAFUKU, Masaki MASUDA, Kazuki KAWAGUCHI, Takeshi SASAKI
  • Patent number: 9431680
    Abstract: An electric storage device includes: a rolled electrode assembly 10 formed by winding a positive electrode, a negative electrode, and a separator so as to have curved portions and linear portions; current collectors 7; and an electrolyte solution 3. A positive electrode substrate has at one end 10A an unformed portion 11E formed without a positive electrode mixture layer, and a negative electrode substrate has at the other end 10B an unformed portion 13E formed without a negative electrode mixture layer. The current collectors 7 are connected respectively to at least part of the linear portions in the unformed portion of the positive electrode at the one end 10A and that of the negative electrode at the other end 10B. The one end 10A in the positive electrode has a length greater than the winding length, and/or the other end 10B in the negative electrode has such a length.
    Type: Grant
    Filed: January 10, 2014
    Date of Patent: August 30, 2016
    Assignee: GS YUASA INTERNATIONAL LTD.
    Inventors: Takeshi Sasaki, Taro Yamafuku
  • Publication number: 20160172646
    Abstract: An energy storage apparatus includes: an energy storage device including a flat electrode assembly in which electrodes are layered and a prismatic case in which the electrode assembly is housed; and a spacer arranged adjacently to the energy storage device in a first direction, wherein the spacer is formed such that a thickness size in the first direction of a center portion of the spacer in a second direction, which is a direction orthogonal to the first direction and is a direction parallel to a surface of the spacer that faces the energy storage device, is set larger than a thickness size in the first direction of other portions of the spacer arranged adjacently to the center portion of the spacer in the second direction, and a width of the center portion of the spacer in a third direction orthogonal to the first and second directions at a contact portion of the spacer with the energy storage device is set smaller than a width of the case in the third direction.
    Type: Application
    Filed: November 30, 2015
    Publication date: June 16, 2016
    Inventors: Taro YAMAFUKU, Takeshi SASAKI
  • Publication number: 20160093859
    Abstract: An energy storage device includes: an electrode having a composite layer formed by applying a composite directly or indirectly onto a substrate and a non-applied portion, onto which the composite is not applied; and a separator layered on the electrode to face the composite layer. Here, a drawn area is formed in at least. a part of the non-applied portion, and an intermediate layer is interposed at least between the drawn area and the composite layer.
    Type: Application
    Filed: September 24, 2015
    Publication date: March 31, 2016
    Inventors: Kazuki KAWAGUCHI, Masashi TAKANO, Taro YAMAFUKU, Masaki MASUDA