Patents by Inventor Takahiro Kawakami

Takahiro Kawakami 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: 20200290581
    Abstract: Provided is a braking device capable of increasing boost responsiveness of wheel cylinders. The braking device includes a second chamber from which a brake fluid is discharged by a movement of a piston caused by inflow of the brake fluid flowed out from a master cylinder to a first chamber through a brake operation by a driver, and a pump configured to discharge the brake fluid into an oil passage for supplying the brake fluid flowed out from the second chamber to a wheel cylinder.
    Type: Application
    Filed: August 3, 2016
    Publication date: September 17, 2020
    Inventors: Takahiro KAWAKAMI, Chiharu NAKAZAWA
  • Publication number: 20200295349
    Abstract: A positive electrode active material which can improve cycle characteristics of a secondary battery is provided. Two kinds of regions are provided in a superficial portion of a positive electrode active material such as lithium cobaltate which has a layered rock-salt crystal structure. The inner region is a non-stoichiometric compound containing a transition metal such as titanium, and the outer region is a compound of representative elements such as magnesium oxide. The two kinds of regions each have a rock-salt crystal structure. The inner layered rock-salt crystal structure and the two kinds of regions in the superficial portion are topotaxy; thus, a change of the crystal structure of the positive electrode active material generated by charging and discharging can be effectively suppressed.
    Type: Application
    Filed: May 28, 2020
    Publication date: September 17, 2020
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Patent number: 10749174
    Abstract: To increase capacity per weight of a power storage device, a particle includes a first region, a second region in contact with at least part of a surface of the first region and located on the outside of the first region, and a third region in contact with at least part of a surface of the second region and located on the outside of the second region. The first and the second regions contain lithium and oxygen. At least one of the first region and the second region contains manganese. At least one of the first and the second regions contains an element M. The first region contains a first crystal having a layered rock-salt structure. The second region contains a second crystal having a layered rock-salt structure. An orientation of the first crystal is different from an orientation of the second crystal.
    Type: Grant
    Filed: August 28, 2018
    Date of Patent: August 18, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takahiro Kawakami, Teruaki Ochiai, Shuhei Yoshitomi, Takuya Hirohashi, Mako Motoyoshi, Yohei Momma, Junya Goto
  • Publication number: 20200259183
    Abstract: In manufacture of a storage battery electrode containing graphene as a conductive additive, the efficiency of reduction of graphene oxide under mild conditions is increased, and cycle characteristics and rate characteristics of a storage battery are improved. Provided is a manufacturing method of a storage battery electrode. In the manufacturing method, a first mixture containing an active material, graphene oxide, and a solvent is formed; a reducing agent is added to the first mixture and the graphene oxide is reduced to form a second mixture; a binder is mixed with the second mixture to form a third mixture; and the third mixture is applied to a current collector and the solvent is evaporated to form an active material layer.
    Type: Application
    Filed: April 29, 2020
    Publication date: August 13, 2020
    Inventors: Tatsuya IKENUMA, Takahiro KAWAKAMI, Yohei MOMMA, Teruaki OCHIAI
  • Publication number: 20200254989
    Abstract: Provided is a hydraulic pressure control device capable of improving ease of layout. The hydraulic pressure control device includes a stroke simulator unit and a hydraulic pressure unit. The stroke simulator unit includes a stroke simulator, a simulator connection liquid passage, and a simulator connection port. The stroke simulator is independent of a master cylinder configured to generate a hydraulic pressure through a brake pedal operation, and is configured to generate a reaction force against the brake pedal operation. The simulator connection liquid passage has one end side connected to the stroke simulator, and an opposite end side. The simulator connection port is provided on the opposite end side of the simulator connection liquid passage. The stroke simulator unit is mounted to the hydraulic pressure unit. The hydraulic pressure unit includes a unit connection port and a liquid passage.
    Type: Application
    Filed: October 24, 2016
    Publication date: August 13, 2020
    Inventors: Takahiro KAWAKAMI, Ryohei MARUO, Chiharu NAKAZAWA
  • Patent number: 10741828
    Abstract: A positive electrode active material which can improve cycle characteristics of a secondary battery is provided. Two kinds of regions are provided in a superficial portion of a positive electrode active material such as lithium cobaltate which has a layered rock-salt crystal structure. The inner region is a non-stoichiometric compound containing a transition metal such as titanium, and the outer region is a compound of representative elements such as magnesium oxide. The two kinds of regions each have a rock-salt crystal structure. The inner layered rock-salt crystal structure and the two kinds of regions in the superficial portion are topotaxy; thus, a change of the crystal structure of the positive electrode active material generated by charging and discharging can be effectively suppressed.
    Type: Grant
    Filed: June 30, 2017
    Date of Patent: August 11, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Teruaki Ochiai, Takahiro Kawakami, Mayumi Mikami, Yohei Momma, Masahiro Takahashi, Ayae Tsuruta
  • Publication number: 20200185763
    Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer over the positive electrode current collector. The positive electrode active material layer includes a plurality of lithium-containing composite oxides each of which is expressed by LiMPO4 (M is one or more of Fe (II), Mn (II), Co (II), and Ni (II)) that is a general formula. The lithium-containing composite oxide is a flat single crystal particle in which the length in the b-axis direction is shorter than each of the lengths in the a-axis direction and the c-axis direction. The lithium-containing composite oxide is provided over the positive electrode current collector so that the b-axis of the single crystal particle intersects with the surface of the positive electrode current collector.
    Type: Application
    Filed: February 14, 2020
    Publication date: June 11, 2020
    Inventors: Tomoya FUTAMURA, Tamae MORIWAKA, Takahiro KAWAKAMI, Junpei MOMO, Nobuhiro INOUE
  • Publication number: 20200119334
    Abstract: A positive electrode for a nonaqueous secondary battery including an active material layer which has sufficient electron conductivity with a low ratio of a conductive additive is provided. A positive electrode for a nonaqueous secondary battery including an active material layer which is highly filled with an active material, id est, including the active material and a low ratio of a conductive additive. The active material layer includes a plurality of particles of an active material with a layered rock salt structure, graphene that is in surface contact with the plurality of particles of the active material, and a binder.
    Type: Application
    Filed: December 11, 2019
    Publication date: April 16, 2020
    Inventors: Takahiro KAWAKAMI, Masaki YAMAKAJI, Mako MOTOYOSHI, Rika YATABE
  • Patent number: 10615404
    Abstract: To provide a fabricating method and a fabricating apparatus for a lithium-ion secondary battery having stable charge characteristics and lifetime characteristics. A positive electrode is subjected to an electrochemical reaction in a large amount of electrolytic solution in advance before a secondary battery is completed. In this manner, the positive electrode can have stability. The use of the positive electrode enables fabrication of a highly reliable secondary battery. Similarly, a negative electrode is subjected to an electrochemical reaction in a large amount of electrolytic solution in advance. The use of the negative electrode enables fabrication of a highly reliable secondary battery.
    Type: Grant
    Filed: May 8, 2019
    Date of Patent: April 7, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yohei Momma, Junpei Momo, Minoru Takahashi, Takahiro Kawakami
  • Publication number: 20200106093
    Abstract: Provided is a positive electrode active material which suppresses a reduction in capacity due to charge and discharge cycles when used in a lithium ion secondary battery. A covering layer is formed by segregation on a superficial portion of the positive electrode active material. The positive electrode active material includes a first region and a second region. The first region exists in an inner portion of the positive electrode active material. The second region exists in a superficial portion of the positive electrode active material and part of the inner portion thereof. The first region includes lithium, a transition metal, and oxygen. The second region includes magnesium, fluorine, and oxygen.
    Type: Application
    Filed: December 4, 2019
    Publication date: April 2, 2020
    Inventors: Takahiro KAWAKAMI, Teruaki OCHIAI, Yohei MOMMA, Ayae TSURUTA, Masahiro TAKAHASHI, Mayumi MIKAMI
  • Patent number: 10608248
    Abstract: The volume density or weight density of lithium ions that can be received and released in and from a positive electrode active material is increased to achieve high capacity and high energy density of a secondary battery. In a lithium manganese composite oxide, each particle includes a first region including a crystal with a layered rock-salt crystal structure and a second region including a crystal with a spinel crystal structure. The second region is in contact with the outside of the first region. The lithium manganese composite oxide has high structural stability and high capacity.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: March 31, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takahiro Kawakami, Tatsuya Ikenuma, Satoshi Seo
  • Patent number: 10593929
    Abstract: To provide a fabricating method and a fabricating apparatus for a lithium-ion secondary battery having stable charge characteristics and lifetime characteristics. A positive electrode is subjected to an electrochemical reaction in a large amount of electrolytic solution in advance before a secondary battery is completed. In this manner, the positive electrode can have stability. The use of the positive electrode enables fabrication of a highly reliable secondary battery. Similarly, a negative electrode is subjected to an electrochemical reaction in a large amount of electrolytic solution in advance. The use of the negative electrode enables fabrication of a highly reliable secondary battery.
    Type: Grant
    Filed: July 1, 2015
    Date of Patent: March 17, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yohei Momma, Junpei Momo, Minoru Takahashi, Takahiro Kawakami
  • Patent number: 10566649
    Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer over the positive electrode current collector. The positive electrode active material layer includes a plurality of lithium-containing, composite oxides each of which is expressed by LiMPO4 (M is one or more of Fe (II), Mn (II), Co (II), and Ni (II)) that is a general formula. The lithium-containing composite oxide is a flat single crystal particle in which the length in the b-axis direction is shorter than each of the lengths in the a-axis direction and the c-axis direction. The lithium-containing composite oxide is provided over the positive electrode current collector so that the b-axis of the single crystal particle intersects with the surface of the positive electrode current collector.
    Type: Grant
    Filed: May 30, 2017
    Date of Patent: February 18, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Tomoya Futamura, Tamae Moriwaka, Takahiro Kawakami, Junpei Momo, Nobuhiro Inoue
  • Publication number: 20200052299
    Abstract: The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.
    Type: Application
    Filed: October 11, 2019
    Publication date: February 13, 2020
    Inventors: Hiroatsu TODORIKI, Yumiko SAITO, Takahiro KAWAKAMI, Kuniharu NOMOTO, Mikio YUKAWA
  • Patent number: 10513005
    Abstract: A power tool, such as a grinder, includes a motor housing that houses a motor. A grip housing extends in a longitudinal direction of the power tool and has a first longitudinal end coupled to the motor housing, first and second battery-mount parts formed at a second longitudinal end, and a grip part disposed between the first and second longitudinal ends. First and second battery packs are respectively mountable on the first and second battery-mount parts, and the grip housing comprises an upper housing half joined to a lower housing half.
    Type: Grant
    Filed: October 17, 2017
    Date of Patent: December 24, 2019
    Assignee: MAKITA CORPORATION
    Inventors: Takahiro Kawakami, Yoshinori Sasaki
  • Publication number: 20190363338
    Abstract: In manufacturing a storage battery electrode, a method for manufacturing a storage battery electrode with high capacity and stability is provided. As a method for preventing a mixture for forming an active material layer from becoming strongly basic, a first aqueous solution is formed by mixing an active material exhibiting basicity with an aqueous solution exhibiting acidity and including an oxidized derivative of a first conductive additive; a first mixture is formed by reducing the oxidized derivative of the first conductive additive by drying the first aqueous solution; a second mixture is formed by mixing a second conductive additive and a binder; a third mixture is formed by mixing the first mixture and the second mixture; and a current collector is coated with the third mixture. The strong basicity of the mixture for forming an active material layer is lowered; thus, the binder can be prevented from becoming gelled.
    Type: Application
    Filed: July 25, 2019
    Publication date: November 28, 2019
    Inventors: Takahiro KAWAKAMI, Yohei MOMMA, Teruaki OCHIAI, Tatsuya IKENUMA
  • Publication number: 20190329748
    Abstract: An object of the present invention is to provide a hydraulic control apparatus capable of layout flexibility. A hydraulics control apparatus includes a second unit (a hydraulic unit) and a first unit (a stroke simulator unit). The second unit includes a housing including a brake fluid passage therein, a positive pressure fluid passage and a back-pressure fluid passage (a unit connection fluid passage) each having one end side connected to the brake fluid passage, a positive pressure port and a back-pressure port (a unit connection port) provided on a surface of the housing and connected to the other end sides of the positive pressure fluid passage and the back-pressure fluid passage, a pump (a hydraulic source) provided inside the housing and configured to generate a hydraulic pressure in each of wheel cylinders of a vehicle via the brake fluid passage, and a motor attached to a surface of the housing and configured to actuate the pump. The first unit includes a stroke simulator.
    Type: Application
    Filed: June 15, 2017
    Publication date: October 31, 2019
    Inventors: Takahiro KAWAKAMI, Ryohei MARUO, Chiharu NAKAZAWA
  • Patent number: 10461332
    Abstract: The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.
    Type: Grant
    Filed: October 7, 2014
    Date of Patent: October 29, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiroatsu Todoriki, Yumiko Saito, Takahiro Kawakami, Kuniharu Nomoto, Mikio Yukawa
  • Patent number: 10454102
    Abstract: To increase the volume density or weight density of lithium ions that can be received and released in and from a positive electrode active material to achieve high capacity and high energy density of a secondary battery. A lithium manganese composite oxide represented by LixMnyMzOw that includes a region belonging to a space group C2/c and is covered with a carbon-containing layer is used as the positive electrode active material. The element M is an element other than lithium and manganese. The lithium manganese composite oxide has high structural stability and high capacity.
    Type: Grant
    Filed: July 13, 2017
    Date of Patent: October 22, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Tatsuya Ikenuma, Shuhei Yoshitomi, Takahiro Kawakami, Yumiko Yoneda, Yohei Momma
  • Publication number: 20190296334
    Abstract: A negative electrode and a secondary battery including the negative electrode are provided. A plurality of projections and depressions are provided in a negative electrode active material layer and a negative electrode current collector. The plurality of projections and depressions in the negative electrode active material layer absorb expansion of the negative electrode active material and suppress deformation thereof. The plurality of projections and depressions in the negative electrode current collector suppress deformation of the negative electrode current collector caused by expansion and contraction of the negative electrode active material.
    Type: Application
    Filed: June 10, 2019
    Publication date: September 26, 2019
    Inventors: Junya GOTO, Mako MOTOYOSHI, Yuika SATO, Takahiro KAWAKAMI