Patents by Inventor Katsumi Maeda

Katsumi Maeda 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).

  • Patent number: 10497978
    Abstract: A secondary battery exhibiting high charge and discharge rate characteristics can be provided, by making the secondary battery have a cathode including a nitroxyl compound taking a nitroxyl cation substructure represented by the following formula (1) in an oxidized state and a nitroxyl radical substructure represented by the following formula (2) in a reduced state, an anode including an active material capable of reversibly intercalating and deintercalating a lithium ion, and an electrolyte solution including a lithium salt and an aprotic organic solvent, and employing Li[(FSO2)2N] as the lithium salt:
    Type: Grant
    Filed: February 23, 2016
    Date of Patent: December 3, 2019
    Assignee: NEC Corporation
    Inventors: Terumasa Shimoyama, Takanori Nishi, Shigeyuki Iwasa, Katsumi Maeda
  • Publication number: 20190312306
    Abstract: In order to provide a lithium ion secondary battery having both high energy density and an excellent charging-rate characteristic, in the lithium ion secondary battery comprising a positive electrode, a negative electrode and an electrolyte solution, the electrolyte solution comprises 0.5 mol/l or more of Li[(FSO2)2N], 0.5 mol/l or more of LiPF6, and LiPO2F2; and the negative electrode comprises graphite deposited with amorphous carbon or graphite coated with amorphous carbon and having a specific surface area of 4 m2/g or less, as a negative electrode active material.
    Type: Application
    Filed: June 13, 2017
    Publication date: October 10, 2019
    Applicant: NEC Corporation
    Inventors: Noriyuki TAMURA, Katsumi MAEDA, Qian CHENG
  • Publication number: 20190305317
    Abstract: The object of the invention is to provide a new lithium ion battery system that can have both high energy density and fast chargeable capability. The invention provides a lithium ion battery, comprising an anode comprising an anode active material layer on an anode current collector, the anode active material layer having a mass load higher than 60 g/m2, a cathode comprising a cathode active material layer on a cathode current collector, the cathode active material layer having a mass load higher than 100 g/m2, and an electrolytic solution comprising an imide anion based lithium salt and LiPO2F2, wherein at least one of the anode and cathode active material layers comprises a spacer composed of a hard carbon.
    Type: Application
    Filed: October 6, 2016
    Publication date: October 3, 2019
    Applicant: NEC CORPORATION
    Inventors: Qian CHENG, Katsumi MAEDA, Noriyuki TAMURA
  • Publication number: 20190280300
    Abstract: An electrode for lithium ion secondary batteries, including a porous glass particle and a positive electrode active material or negative electrode active material that is capable of occluding and releasing lithium ions wherein the pore volume of the porous glass particle is from 0.1 ml/g to 2 ml/g, is used to provide a lithium ion secondary battery excellent in a charge rate property.
    Type: Application
    Filed: October 25, 2017
    Publication date: September 12, 2019
    Applicant: NEC CORPORATION
    Inventors: Katsumi MAEDA, Noriyuki TAMURA, Mika SHIBA
  • Patent number: 10374258
    Abstract: A nonaqueous electrolytic solution comprising a cyclobutenedione derivative represented by the following general formula (1): wherein R1 represents an organic group having a carbon-carbon double bond or a carbon-carbon triple bond in its structure, and R2 represents an alkyl group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms, a thioalkyl group having 1-6 carbon atoms, a substituted or unsubstituted thioaryl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group.
    Type: Grant
    Filed: July 1, 2015
    Date of Patent: August 6, 2019
    Assignee: NEC Corporation
    Inventors: Katsumi Maeda, Shizuka Sato, Mika Horie
  • Patent number: 10374259
    Abstract: A nonaqueous electrolyte solution including a hydrofluoroether compound represented by the following formula (1): [Formula 1] CF3CF2CF2OCHFCF2OR1??(1) wherein R1 represents a difluoromethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a 1,1,1,3,3,3-hexafluoroisopropyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, a 2,2,3,3,4,4-hexafluorobutyl group, or a 2,2,3,3,4,4,5,5-octafluoropentyl group.
    Type: Grant
    Filed: March 2, 2016
    Date of Patent: August 6, 2019
    Assignee: NEC Corporation
    Inventor: Katsumi Maeda
  • Publication number: 20190181494
    Abstract: A nonaqueous electrolytic solution comprising a nonaqueous solvent, an electrolyte, lithium difluorophosphate, and a difluoroboron complex compound represented by general formula (1): wherein R1 and R2 each independently represent a substituted or unsubstituted alkyl group having one to six carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkoxy group, and R3 represents a hydrogen atom, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, wherein the content of lithium bis(fluorosulfonyl)imide as the electrolyte is 0 to 80 mol % based on the total amount of moles of the electrolyte.
    Type: Application
    Filed: July 14, 2017
    Publication date: June 13, 2019
    Applicant: NEC CORPORATION
    Inventors: Katsumi MAEDA, Qian CHENG
  • Publication number: 20190044182
    Abstract: Provided are a lithium secondary battery high in capacity and excellent in charge and discharge rate characteristics, and a method for producing the same. The lithium secondary battery of the present invention includes a positive electrode containing a positive electrode active substance containing a lithium transition metal oxide, a negative electrode containing a negative electrode active substance containing a heat-treated graphite material, and an electrolytic solution, wherein the heat-treated graphite material has passages of lithium ions penetrating at least one or more layers of graphene layers from the surface of a graphene stacking structure; and the electrolytic solution contains lithium difluorophosphate.
    Type: Application
    Filed: August 8, 2016
    Publication date: February 7, 2019
    Applicant: NEC CORPORATION
    Inventors: Katsumi MAEDA, Noriyuki TAMURA, Mika SHIBA
  • Publication number: 20190027741
    Abstract: Provided are a positive electrode active material capable of inhibiting generation of gases accompanied by charging/discharging, a positive electrode and a lithium secondary cell using the positive electrode active material, and methods for manufacturing the positive electrode active material, the positive electrode, and the lithium secondary cell. The positive electrode active material comprises a coated positive electrode active material having a coating comprising at least one selected from specific phosphonic esters and specific phosphorous triesters.
    Type: Application
    Filed: December 19, 2016
    Publication date: January 24, 2019
    Applicant: NEC CORPORATION
    Inventors: Katsumi MAEDA, Sadanori HATTORI
  • Publication number: 20180351199
    Abstract: An object of the present invention is to provide a positive electrode active substance capable of suppressing gas generation associated with charge and discharge in a lithium secondary battery, and capable of suppressing gas generation associated with charge and discharge particularly even in cases where the use voltage of the lithium secondary battery is high, a positive electrode and a lithium secondary battery using the positive electrode active substance, and methods for producing these. The present invention is a positive electrode active substance for a lithium secondary battery, comprising a coated positive electrode active substance wherein a surface of a positive electrode active substance is directly coated with lithium metaphosphate.
    Type: Application
    Filed: October 31, 2016
    Publication date: December 6, 2018
    Applicant: NEC CORPORATION
    Inventors: Katsumi MAEDA, Sadanori HATTORI
  • Patent number: 10128538
    Abstract: The present invention provides a non-aqueous electrolytic solution comprising a phosphinoamine-based compound represented by formula (1) below and a lithium ion secondary battery comprising the non-aqueous electrolytic solution. By adding the phosphinoamine-based compound to the non-aqueous electrolytic solution, oxidative degradation in the non-aqueous electrolytic solution is suppressed, and thus gas generation is suppressed.
    Type: Grant
    Filed: June 11, 2015
    Date of Patent: November 13, 2018
    Assignee: NEC Corporation
    Inventors: Shizuka Sato, Katsumi Maeda, Noriyuki Tamura, Sadanori Hattori
  • Patent number: 10069166
    Abstract: The present invention relates to a non-aqueous electrolyte solution characterized by containing at least one type of cyclic sulfonic acid ester compound represented by general formula (1). According to the present invention, a non-aqueous electrolyte solution capable of improving battery characteristics can be provided. (In the formula, R1 to R4 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1-6 carbon atoms or an alkoxy group having 1-6 carbon atoms, and Z is a substituted or unsubstituted alkylene group having 1-6 carbon atoms, a substituted or unsubstituted fluoroalkylene group having 1-6 carbon atoms, or a divalent organic group having 2-6 carbon atoms in which alkylene unit(s) or fluoroalkylene unit(s) are bonded via one or more ether bonds.
    Type: Grant
    Filed: December 16, 2014
    Date of Patent: September 4, 2018
    Assignee: NEC Corporation
    Inventors: Katsumi Maeda, Kentaro Nakahara
  • Patent number: 10050309
    Abstract: A nonaqueous electrolytic solution comprising a nonaqueous solvent, an electrolyte salt comprising a lithium salt, and a difluoroboron complex compound represented by the following general formula (1): wherein R1 and R2 each independently represent a substituted or unsubstituted alkyl group having 1-6 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkoxy group, and R3 represents a hydrogen atom, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group.
    Type: Grant
    Filed: July 1, 2015
    Date of Patent: August 14, 2018
    Assignee: NEC Corporation
    Inventor: Katsumi Maeda
  • Publication number: 20180183099
    Abstract: The present invention provides a non-aqueous electrolytic solution comprising a phosphinoamine-based compound represented by formula (1) below and a lithium ion secondary battery comprising the non-aqueous electrolytic solution. By adding the phosphinoamine-based compound to the non-aqueous electrolytic solution, oxidative degradation in the non-aqueous electrolytic solution is suppressed, and thus gas generation is suppressed.
    Type: Application
    Filed: June 11, 2015
    Publication date: June 28, 2018
    Applicant: NEC Corporation
    Inventors: Shizuka SATO, Katsumi MAEDA, Noriyuki TAMURA, Sadanori HATTORI
  • Publication number: 20180145371
    Abstract: In terms of a lithium ion secondary battery using, in a positive electrode, a lithium transition metal composite oxide containing an over-stoichiometric amount of lithium, a lithium ion secondary battery in which an amount of a gas generated during charge/discharge cycles is reduced and capacity retention is improved is provided. The lithium ion secondary battery includes a positive electrode containing a lithium transition metal composite oxide containing Fe and containing an over-stoichiometric amount of lithium, and a nonaqueous electrolyte solution, and the nonaqueous electrolyte solution contains a nonaqueous organic solvent, an electrolyte, and lithium difluorophosphate.
    Type: Application
    Filed: June 23, 2016
    Publication date: May 24, 2018
    Applicant: NEC CORPORATION
    Inventors: Katsumi MAEDA, Noriyuki TAMURA, Sadanori HATTORI
  • Publication number: 20180115018
    Abstract: A secondary battery exhibiting high charge and discharge rate characteristics can be provided, by making the secondary battery have a cathode including a nitroxyl compound taking a nitroxyl cation substructure represented by the following formula (1) in an oxidized state and a nitroxyl radical substructure represented by the following formula (2) in a reduced state, an anode including an active material capable of reversibly intercalating and deintercalating a lithium ion, and an electrolyte solution including a lithium salt and an aprotic organic solvent, and employing Li[(FSO2)2N] as the lithium salt:
    Type: Application
    Filed: February 23, 2016
    Publication date: April 26, 2018
    Applicant: NEC Corporation
    Inventors: Terumasa SHIMOYAMA, Takanori NISHI, Shigeyuki IWASA, Katsumi MAEDA
  • Publication number: 20180115020
    Abstract: A nonaqueous electrolyte solution including a hydrofluoroether compound represented by the following formula (1): [Formula 1] CF3CF2CF2OCHFCF2OR1??(1) wherein R1 represents a difluoromethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a 1,1,1,3,3,3-hexafluoroisopropyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, a 2,2,3,3,4,4-hexafluorobutyl group, or a 2,2,3,3,4,4,5,5-octafluoropentyl group.
    Type: Application
    Filed: March 2, 2016
    Publication date: April 26, 2018
    Applicant: NEC Corporation
    Inventor: Katsumi MAEDA
  • Patent number: 9812735
    Abstract: A lithium ion secondary battery comprising: a positive electrode comprising a positive electrode active material; a negative electrode comprised mainly of a material capable of storing and releasing lithium ions; and an electrolytic liquid, the positive electrode active material being a lithium-iron-manganese complex oxide having a layered rock salt structure and represented by a chemical formula: LixFesM1(z-s)M2yO2-? wherein 1.05?x?1.32, 0.06?s?0.50, 0.06?z?0.50, 0.33?y?0.63, and 0???0.
    Type: Grant
    Filed: August 20, 2014
    Date of Patent: November 7, 2017
    Assignees: SEKISUI CHEMICAL CO., LTD., NEC CORPORATION
    Inventors: Masaru Heishi, Takuya Toyokawa, Katsumi Maeda, Noriyuki Tamura, Kentaro Nakahara
  • Publication number: 20170271712
    Abstract: A positive electrode active material for a lithium ion secondary battery that can suppress gas generation and that can provide a lithium ion secondary battery having a high capacity retention ratio in charge-discharge cycles is provided. The positive electrode active material for a lithium ion secondary battery according to the present exemplary embodiment includes a compound having a layered rock salt structure and represented by LixFesM1(z-s)M2yO? (wherein 1.05?x?1.90, 0.05?s?0.50, 0.05?z?0.50, 0.33?y?0.90, 1.20???3.10 and z?s?0; M1 is at least one element selected from the group consisting of Co and Ni; and M2 is at least one element selected from the group consisting of Mn, Ti and Zr) and a specific 1,3-propanedione derivative.
    Type: Application
    Filed: September 17, 2015
    Publication date: September 21, 2017
    Applicant: NEC Corporation
    Inventors: Katsumi MAEDA, Sadanori HATTORI, Noriyuki TAMURA
  • Publication number: 20170210764
    Abstract: A nonaqueous electrolytic solution comprising a cyclobutenedione derivative represented by the following general formula (1): wherein R1 represents an organic group having a carbon-carbon double bond or a carbon-carbon triple bond in its structure, and R2 represents an alkyl group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms, a thioalkyl group having 1-6 carbon atoms, a substituted or unsubstituted thioaryl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group.
    Type: Application
    Filed: July 1, 2015
    Publication date: July 27, 2017
    Applicant: NEC Corporation
    Inventors: Katsumi MAEDA, Shizuka SATO, Mika HORIE