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: 20220200041
    Abstract: Positive electrode active material particles that inhibit a decrease in capacity due to charge and discharge cycles are provided. A high-capacity secondary battery, a secondary battery with excellent charge and discharge characteristics, or a highly-safe or highly-reliable secondary battery is provided. A novel material, active material particles, and a storage device are provided. The positive electrode active material particle includes a first region and a second region in contact with the outside of the first region. The first region contains lithium, oxygen, and an element M that is one or more elements selected from cobalt, manganese, and nickel. The second region contains the element M, oxygen, magnesium, and fluorine. The atomic ratio of lithium to the element M (Li/M) measured by X-ray photoelectron spectroscopy is 0.5 or more and 0.85 or less. The atomic ratio of magnesium to the element M (Mg/M) is 0.2 or more and 0.5 or less.
    Type: Application
    Filed: March 8, 2022
    Publication date: June 23, 2022
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Ayae TSURUTA, Masahiro TAKAHASHI
  • Publication number: 20220199989
    Abstract: Provided is a positive electrode active material for a lithium ion secondary battery having favorable cycle characteristics and high capacity. A covering layer containing aluminum and a covering layer containing magnesium are provided on a superficial portion of the positive electrode active material. The covering layer containing magnesium exists in a region closer to a particle surface than the covering layer containing aluminum is. The covering layer containing aluminum can be formed by a sol-gel method using an aluminum alkoxide. The covering layer containing magnesium can be formed as follows: magnesium and fluorine are mixed as a starting material and then subjected to heating after the sol-gel step, so that magnesium is segregated.
    Type: Application
    Filed: March 8, 2022
    Publication date: June 23, 2022
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Yohei MOMMA, Takahiro KAWAKAMI, Teruaki OCHIAI, Masahiro TAKAHASHI
  • Publication number: 20220199983
    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: March 7, 2022
    Publication date: June 23, 2022
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takahiro KAWAKAMI, Teruaki OCHIAI, Yohei MOMMA, Ayae TSURUTA, Masahiro Takahashi, Mayumi MIKAMI
  • Publication number: 20220190313
    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: March 7, 2022
    Publication date: June 16, 2022
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki Ochiai, Takahiro Kawakami, Mayumi Mikami, Yohei Momma, Masahiro Takahashi, Ayae Tsuruta
  • Patent number: 11335945
    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: February 14, 2020
    Date of Patent: May 17, 2022
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Tomoya Futamura, Tamae Moriwaka, Takahiro Kawakami, Junpei Momo, Nobuhiro Inoue
  • Patent number: 11322746
    Abstract: A novel electrode is provided. A novel power storage device is provided. A conductor having a sheet-like shape is provided. The conductor has a thickness of greater than or equal to 800 nm and less than or equal to 20 ?m. The area of the conductor is greater than or equal to 25 mm2 and less than or equal to 10 m2. The conductor includes carbon and oxygen. The conductor includes carbon at a concentration of higher than 80 atomic % and oxygen at a concentration of higher than or equal to 2 atomic % and lower than or equal to 20 atomic %.
    Type: Grant
    Filed: July 23, 2020
    Date of Patent: May 3, 2022
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Teruaki Ochiai, Takahiro Kawakami, Takuya Miwa
  • Publication number: 20220115637
    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: December 23, 2021
    Publication date: April 14, 2022
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20220059824
    Abstract: A positive electrode for a secondary battery which enables both good battery characteristics and electrode strength at a predetermined level, a secondary battery, and a method for fabricating the positive electrode for a secondary battery are provided. The positive electrode for a secondary battery includes a current collector and an active material layer over the current collector. The active material layer includes an active material, graphene, and a binder. A carbon layer is on a surface of the active material. The proportion of the graphene in the active material layer is greater than or equal to 0.1 wt % and less than or equal to 1.0 wt %.
    Type: Application
    Filed: August 30, 2021
    Publication date: February 24, 2022
    Inventors: Masaki YAMAKAJI, Takahiro KAWAKAMI, Mako MOTOYOSHI, Rika YATABE
  • Patent number: 11172676
    Abstract: An antibacterial resin composition comprising a thermoplastic resin or a thermosetting resin blended with a metal-carrying compound carrying at least one kind of metal ions selected from the group consisting of Ag, Cu, Zn, Co, and Ni, and a compound represented by the following formula (2): wherein M? is any one of Na, K, or H, and X is an atom selected from the group consisting of C, O, S, and P, or an atomic group thereof.
    Type: Grant
    Filed: January 15, 2018
    Date of Patent: November 16, 2021
    Assignee: TOYO SEIKAN GROUP HOLDINGS, LTD.
    Inventors: Kazuaki Ohashi, Yasuhiro Kosaka, Akiko Ogata, Takahiro Kawakami
  • Publication number: 20210339724
    Abstract: A stroke simulator is configured in such a manner that an elastic member disposed in a cylinder of the stroke simulator is restricted from being deformed in a radial direction of the cylinder.
    Type: Application
    Filed: August 5, 2019
    Publication date: November 4, 2021
    Inventors: Ryohei MARUO, Takahiro KAWAKAMI
  • Publication number: 20210320290
    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: October 7, 2020
    Publication date: October 14, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Teruaki OCHIAI, Takahiro KAWAKAMI, Mayumi MIKAMI, Yohei MOMMA, Masahiro TAKAHASHI, Ayae TSURUTA
  • Publication number: 20210305553
    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: June 11, 2021
    Publication date: September 30, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takahiro KAWAKAMI, Teruaki OCHIAI, Yohei MOMMA, Ayae TSURUTA, Masahiro Takahashi, Mayumi MIKAMI
  • Patent number: 11108038
    Abstract: A positive electrode for a secondary battery which enables both good battery characteristics and electrode strength at a predetermined level, a secondary battery, and a method for fabricating the positive electrode for a secondary battery are provided. The positive electrode for a secondary battery includes a current collector and an active material layer over the current collector. The active material layer includes an active material, graphene, and a binder. A carbon layer is on a surface of the active material. The proportion of the graphene in the active material layer is greater than or equal to 0.1 wt % and less than or equal to 1.0 wt %.
    Type: Grant
    Filed: June 27, 2016
    Date of Patent: August 31, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masaki Yamakaji, Takahiro Kawakami, Mako Motoyoshi, Rika Yatabe
  • Patent number: 11094927
    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: Grant
    Filed: October 6, 2017
    Date of Patent: August 17, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takahiro Kawakami, Teruaki Ochiai, Yohei Momma, Ayae Tsuruta, Masahiro Takahashi, Mayumi Mikami
  • Patent number: 11043660
    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: July 8, 2020
    Date of Patent: June 22, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Teruaki Ochiai, Takahiro Kawakami, Mayumi Mikami, Yohei Momma, Masahiro Takahashi, Ayae Tsuruta
  • Publication number: 20210167353
    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: February 9, 2021
    Publication date: June 3, 2021
    Inventors: Takahiro KAWAKAMI, Yohei MOMMA, Teruaki OCHIAI, Tatsuya IKENUMA
  • Publication number: 20210151758
    Abstract: An object is to improve the characteristics of a power storage device such as a charging and discharging rate or a charge and discharge capacity. The grain size of particles of a positive electrode active material is nano-sized so that a surface area per unit mass of the active material is increased. Specifically, the grain size is set to greater than or equal to 10 nm and less than or equal to 100 nm, preferably greater than or equal to 20 nm and less than or equal to 60 nm. Alternatively, the surface area per unit mass is set to 10 m2/g or more, preferably 20 m2/g or more, further, the crystallinity of the active material is increased by setting an XRD half width to greater than or equal to 0.12° and less than 0.17°, preferably greater than or equal to 0.13° and less than 0.16°.
    Type: Application
    Filed: January 28, 2021
    Publication date: May 20, 2021
    Inventors: Takahiro KAWAKAMI, Masaki YAMAKAJI
  • Patent number: 10994404
    Abstract: An electric tool, such as an angle driver, has a main tool body with a front portion and a rear portion positioned opposite to the front portion. The main tool body houses a motor configured to receive electricity to function as a drive source. A gear head is coupled with the front portion of the main tool body wherein the gear head has a spindle in communication with a motor axis of the motor via mesh-engagement of bevel gears associated with the motor axis. The spindle has with a cutter tool accessory attached thereto such that rotation of the motor axis produces a commensurate rotation of the cutter tool accessory. Battery attachment portions are associated with the rear portion of the main tool body and are configured to receive a corresponding set of batteries that provide electricity to power the motor.
    Type: Grant
    Filed: November 9, 2018
    Date of Patent: May 4, 2021
    Assignee: MAKITA CORPORATION
    Inventors: Miyabi Ito, Ryunosuke Kumagai, Shin Sugiura, Akira Mizutani, Takahiro Kawakami
  • Patent number: 10978696
    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: Grant
    Filed: June 10, 2019
    Date of Patent: April 13, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Junya Goto, Mako Motoyoshi, Yuika Sato, Takahiro Kawakami
  • Patent number: 10978710
    Abstract: A power storage device with excellent charge and discharge characteristics. A power storage device in which a decrease in capacity in charge and discharge cycles is inhibited. An electrode which includes a current collector and an active material layer and in which the active material layer includes an active material and a binder and the binder includes polybenzoxazine. An electrode that includes polybenzoxazine and another material as a binder. A basic material may be used as the active material. The electrode may be formed under high temperatures.
    Type: Grant
    Filed: April 4, 2019
    Date of Patent: April 13, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Teruaki Ochiai, Takahiro Kawakami