Patents by Inventor Kouzou TAKEDA
Kouzou TAKEDA 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).
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Patent number: 10749179Abstract: A graphite-based negative electrode active material including a first graphite particle being spheroidized and a second graphite particle having a roundness lower than the roundness of the first graphite particle, wherein the content of the second graphite particle based on the sum of the first graphite particle and the second graphite particle is in the range of 1 to 30% by mass, the ratio of a median particle diameter (D50) to a particle diameter at 5 cumulative % (D5), D50/D5, in a cumulative distribution of the first graphite particle is smaller than the ratio of a median particle diameter (D50) to a particle diameter at 5 cumulative % (D5), D50/D5, in a cumulative distribution of the second graphite particle, and the tap density in saturation of the particle mixture of the first graphite particle and the second graphite particle is higher than both the tap density in saturation of the first graphite particle and the tap density in saturation of the second graphite particle.Type: GrantFiled: March 30, 2015Date of Patent: August 18, 2020Assignee: ENVISION AESC ENERGY DEVICES LTD.Inventors: Kouzou Takeda, Hiroo Takahashi, Yasutaka Kono
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Patent number: 10714751Abstract: A negative electrode for a lithium ion secondary battery including a current collector and a negative electrode active material layer on the current collector, wherein the negative electrode active material layer includes: a first composite particle with a first graphite core particle and a first non-graphite-based carbon material coating a surface thereof; and a second composite particle with a second graphite core particle and a second non-graphite-based carbon material coating a surface thereof, and wherein an average particle diameter of the first composite particles is 5-30 ?m; an average particle diameter of the second composite particles is 2-25 ?m, and is smaller than the average particle diameter of the first composite particles; the mixing ratio of the first composite particle A and the second composite particle B is 50:50-95:5 in mass ratio; and a density of the negative electrode active material layer is 1.4-1.7 g/cm3.Type: GrantFiled: September 21, 2016Date of Patent: July 14, 2020Assignee: Envision AESC Energy Devices, Ltd.Inventor: Kouzou Takeda
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Publication number: 20200099051Abstract: A negative electrode (100) for a lithium ion battery of the present invention includes a collector layer (101); and a negative electrode active material layer (103) which is provided on at least one surface of the collector layer (101) and contains, as a negative electrode active material, a surface-coated graphite material formed by coating at least apart of a surface with amorphous carbon. Further, a water vapor saturation adsorption amount of the negative electrode active material layer (103) measured using the following method is greater than or equal to 0.03 cm3 (STP)/g and less than or equal to 0.25 cm3 (STP)/g. (Method) The negative electrode active material layer (103) (3.0 g) is dried at 220° C. for 2 hours in a nitrogen atmosphere. Next, the dried negative electrode active material layer (103) is allowed to adsorb water vapor at 25° C. using a constant capacity method, and the water vapor saturation adsorption amount of the negative electrode active material layer (103) is calculated.Type: ApplicationFiled: January 31, 2018Publication date: March 26, 2020Applicant: Envision AESC Energy Devices Ltd.Inventor: Kouzou TAKEDA
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Patent number: 10490818Abstract: A negative electrode for a lithium ion secondary battery, the negative electrode including a negative electrode active material, a fine graphite material, a conductive aid, and a binder, wherein the mass ratio of the fine graphite material to the conductive aid is in the range from 1 to 10, and the average particle diameter (median diameter D50) of the fine graphite material is smaller than the average particle diameter of the negative electrode active material, and in the range of 1 to 15 ?m.Type: GrantFiled: January 20, 2016Date of Patent: November 26, 2019Assignee: Envision AESC Energy Devices Ltd.Inventor: Kouzou Takeda
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Patent number: 10217988Abstract: Provided is a secondary battery with a high electric characteristic and reliability that prevents the short circuit between a positive electrode and a negative electrode by an insulating member and that prevents or reduces the volume increase and deformation of a battery electrode assembly. A secondary battery includes a battery electrode assembly in which positive electrode 1 and negative electrode 6 are alternately laminated while separator 20 is interposed therebetween. Positive electrode 1 and negative electrode 6 include current collectors 3, 8 and active materials 2, 7, each surface of current collectors 3, 8 is provided with an application portion and a non-application portion of active materials 2, 8, and the active materials 2, 7 include a thin portion whose thickness is small.Type: GrantFiled: January 26, 2016Date of Patent: February 26, 2019Assignee: NEC ENERGY DEVICES, LTD.Inventors: Kouzou Takeda, Masaaki Matsuu, Hiroo Takahashi, Yoshimasa Yamamoto, Masanori Hirai
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Publication number: 20180241038Abstract: A negative electrode for a lithium ion secondary battery including a current collector and a negative electrode active material layer on the current collector, wherein the negative electrode active material layer includes: a first composite particle with a first graphite core particle and a first non-graphite-based carbon material coating a surface thereof; and a second composite particle with a second graphite core particle and a second non-graphite-based carbon material coating a surface thereof, and wherein an average particle diameter of the first composite particles is 5-30 ?m; an average particle diameter of the second composite particles is 2-25 ?m, and is smaller than the average particle diameter of the first composite particles; the mixing ratio of the first composite particle A and the second composite particle B is 50:50-95:5 in mass ratio; and a density of the negative electrode active material layer is 1.4-1.7 g/cm3.Type: ApplicationFiled: September 21, 2016Publication date: August 23, 2018Applicant: NEC ENERGY DEVICES, LTD.Inventor: Kouzou TAKEDA
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Publication number: 20170373314Abstract: A negative electrode for a lithium ion secondary battery, the negative electrode including a negative electrode active material, a fine graphite material, a conductive aid, and a binder, wherein the mass ratio of the fine graphite material to the conductive aid is in the range from 1 to 10, and the average particle diameter (median diameter D50) of the fine graphite material is smaller than the average particle diameter of the negative electrode active material, and in the range of 1 to 15 ?m.Type: ApplicationFiled: January 20, 2016Publication date: December 28, 2017Applicant: NEC ENERGY DEVICES, LTD.Inventor: Kouzou TAKEDA
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Publication number: 20170373299Abstract: Provided is a secondary battery with a high electric characteristic and reliability that prevents the short circuit between a positive electrode and a negative electrode by an insulating member and that prevents or reduces the volume increase and deformation of a battery electrode assembly. A secondary battery includes a battery electrode assembly in which positive electrode 1 and negative electrode 6 are alternately laminated while separator 20 is interposed therebetween. Positive electrode 1 and negative electrode 6 include current collectors 3, 8 and active materials 2, 7, each surface of current collectors 3, 8 is provided with an application portion and a non-application portion of active materials 2, 8, and the active materials 2, 7 include a thin portion whose thickness is small.Type: ApplicationFiled: January 26, 2016Publication date: December 28, 2017Applicant: NEC ENERGY DEVICES, LTD.Inventors: Kouzou TAKEDA, Masaaki MATSUU, Hiroo TAKAHASHI, Yoshimasa YAMAMOTO, Masanori HIRAI
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Publication number: 20170187064Abstract: A lithium ion secondary battery including: a positive electrode including a positive electrode active material capable of intercalating and deintercalating a lithium ion; a negative electrode including a negative electrode active material capable of intercalating and deintercalating a lithium ion; and a non-aqueous electrolytic solution, wherein the positive electrode active material includes a Mn-based spinel-type composite oxide and an additional active material, and the content of the Mn-based spinel-type composite oxide based on the whole of the positive electrode active material is 60% by mass or less, and the negative electrode active material includes a first graphite particle containing natural graphite and a second graphite particle containing artificial graphite, and the content of the second graphite particle based on the sum total of the first graphite particle and the second graphite particle is in the range of 1 to 30% by mass.Type: ApplicationFiled: March 30, 2015Publication date: June 29, 2017Applicant: NEC Energy Devices, Ltd.Inventors: Kouzou TAKEDA, Yasutaka KONO, Hiroo TAKAHASHI, Takayuki SUZUKI
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Publication number: 20170179487Abstract: A graphite-based negative electrode active material including a first graphite particle being spheroidized and a second graphite particle having a roundness lower than the roundness of the first graphite particle, wherein the content of the second graphite particle based on the sum of the first graphite particle and the second graphite particle is in the range of 1 to 30% by mass, the ratio of a median particle diameter (D50) to a particle diameter at 5 cumulative % (D5), D50/D5, in a cumulative distribution of the first graphite particle is smaller than the ratio of a median particle diameter (D50) to a particle diameter at 5 cumulative % (D5), D50/D5, in a cumulative distribution of the second graphite particle, and the tap density in saturation of the particle mixture of the first graphite particle and the second graphite particle is higher than both the tap density in saturation of the first graphite particle and the tap density in saturation of the second graphite particle.Type: ApplicationFiled: March 30, 2015Publication date: June 22, 2017Applicant: NEC Energy Devices, Ltd.Inventors: Kouzou TAKEDA, Hiroo TAKAHASHI, Yasutaka KONO