Patents by Inventor Daisuke Kawasaki

Daisuke Kawasaki 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: 11329321
    Abstract: A lithium ion secondary battery having high energy density and being excellent in cycle characteristics is provided. The present invention relates to a lithium ion secondary battery comprising: a negative electrode active material comprising a material comprising silicon as a constituent element; and an electrolyte solution comprising: a non-aqueous solvent comprising a fluorinated ether compound, an open-chain sulfone compound, and a cyclic carbonate compound, and a supporting salt comprising LiPF6, lithium bis(fluorosulfonyl)imide, and lithium bis(oxalato)borate (LiBOB); wherein the content of LiBOB in the electrolyte solution is 0.2 mass % or more.
    Type: Grant
    Filed: May 23, 2018
    Date of Patent: May 10, 2022
    Assignee: NEC CORPORATION
    Inventors: Takehiro Noguchi, Takuya Hasegawa, Ikiko Shimanuki, Daisuke Kawasaki
  • Patent number: 11095149
    Abstract: In an uninterruptible power supply, first connection members that connect input side-switches of a plurality of uninterruptible power supply modules to each other and that connect output-side switches of the plurality of uninterruptible power supply modules to each other, and second connection members connected in parallel to the first connection members are disposed at positions accessible from a front side of the uninterruptible power supply modules.
    Type: Grant
    Filed: July 4, 2017
    Date of Patent: August 17, 2021
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Seiitsu Kin, Daisuke Kawasaki, Yoshihiko Yamagata, Hiroki Muratsu, Tomo Kurozaki, Yosuke Iwamaru, Keita Koshii
  • Publication number: 20210057721
    Abstract: Provided is a lithium ion secondary battery having high energy density and excellent cycle characteristics, and hardly causing burning. The present invention relates to a lithium ion secondary battery comprising an electrode mixture layer comprising an electrode active material comprising Si alloy having a median diameter of 1.2 ?m or less and 12% by weight or more and 50% by weight or less of an electrode binder; and an electrolyte solution comprising 60% by volume or more and 99% by volume or less of a phosphoric acid ester compound, 0% by volume or more and 30% by volume or less of a fluorinated ether compound, and 1% by volume or more and 35% by volume or less of a fluorinated carbonate compound, wherein the total amount of the phosphoric acid ester compound and the fluorinated ether compound is 65% by volume or more.
    Type: Application
    Filed: November 21, 2018
    Publication date: February 25, 2021
    Applicant: NEC CORPORATION
    Inventors: Daisuke KAWASAKI, Takashi OHTSUKA, Kazuhiko INOUE
  • Patent number: 10923770
    Abstract: A purpose of one embodiment of the present invention is to provide a lithium ion secondary battery that has improved life-span characteristics. The first lithium ion secondary battery of the present invention comprises an electrolyte solution comprising a sulfone compound, a fluorinated ether compound and LiN(FSO2)2, and a negative electrode comprising a silicon material, wherein a content of LiN(FSO2)2 in the electrolyte solution is more than 5 weight % and 20 weight % or less.
    Type: Grant
    Filed: November 30, 2017
    Date of Patent: February 16, 2021
    Assignee: NEC CORPORATION
    Inventors: Takehiro Noguchi, Takuya Hasegawa, Daisuke Kawasaki, Ikiko Shimanuki
  • Patent number: 10840551
    Abstract: The present invention relates to a lithium secondary battery having a positive electrode comprising a positive electrode active material capable of absorbing and releasing lithium ions, a negative electrode comprising a negative electrode active material capable of absorbing and releasing lithium ions, and an electrolyte solution, wherein a positive electrode surface detection component comprises at least one negative secondary ion peak selected from CH3S2O6? and CHS2O4?, and further comprises a negative secondary ion peak of SO3—, wherein the positive electrode surface detection component is detected when a primary ion is irradiated on the surface of the positive electrode active material by a Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) method. According to the present invention, it is possible to provide a lithium secondary battery having excellent cycle characteristics.
    Type: Grant
    Filed: August 4, 2015
    Date of Patent: November 17, 2020
    Assignee: NEC Corporation
    Inventors: Ikiko Shimanuki, Hitoshi Ishikawa, Noboru Yoshida, Daisuke Kawasaki
  • Patent number: 10756337
    Abstract: When the particle size of a silicon material used for a negative electrode active material are small, a large surface area thereof easily causes a side reaction between the active material and an electrolyte solvent to occur, and the cycle characteristics of a lithium ion secondary battery decrease. In order to improve the cycle characteristics, a lithium ion secondary battery according to the present invention is characterized in comprising a negative electrode comprising a material comprising silicon as a constituent element and a polyacrylic acid, and an electrolyte solution comprising a fluoroethylene carbonate, wherein the 50% particle size of the material comprising silicon as a constituent element is 2 ?m or less.
    Type: Grant
    Filed: November 29, 2016
    Date of Patent: August 25, 2020
    Assignee: NEC CORPORATION
    Inventors: Ikiko Shimanuki, Suguru Tamai, Daisuke Kawasaki, Hitoshi Ishikawa
  • Patent number: 10749208
    Abstract: The object is to provide a lithium ion secondary battery which has an excellent cycle property even in high-temperature environment and which has small volume increase. An exemplary embodiment of the invention is a lithium ion secondary battery, comprising: a positive electrode, a negative electrode comprising a negative electrode active material, and an electrolyte liquid; wherein the electrolyte liquid comprises a chain-type fluorinated ester compound represented by a predetermined formula and a chain-type fluorinated ether compound represented by a predetermined formula; wherein the negative electrode active material comprises metal (a) that can be alloyed with lithium, metal oxide (b) that can absorb and desorb lithium ion, and carbon material (c) that can absorb and desorb lithium ion; and wherein metal (a) is silicon, and metal oxide (b) is silicon oxide.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: August 18, 2020
    Assignee: NEC CORPORATION
    Inventors: Makiko Uehara, Daisuke Kawasaki, Takehiro Noguchi, Akinobu Nakamura, Kenichi Shimura, Yoko Hashizume
  • Publication number: 20200194776
    Abstract: Provided is a lithium ion secondary battery having high energy density and excellent cycle characteristics. The present invention relates to a negative electrode for a lithium ion secondary battery comprising: (i) a negative electrode mixture layer comprising a negative electrode active material and a negative electrode binder and (ii) a negative electrode current collector, wherein the negative electrode active material comprises an alloy comprising silicon (Si alloy), the Si alloy is crystalline and has a median diameter (D50 particle size) of 1.2 ?m or less, and an amount of the negative electrode binder based on the weight of the negative electrode mixture layer is 12% by weight or more and 50% by weight or less.
    Type: Application
    Filed: August 17, 2018
    Publication date: June 18, 2020
    Applicant: NEC CORPORATION
    Inventors: Daisuke KAWASAKI, Takuya HASEGAWA, Takashi OHTSUKA
  • Publication number: 20200168955
    Abstract: A purpose of the present invention is to provide a lithium ion secondary battery having improved battery characteristics. The lithium ion secondary battery according to the present invention comprises a negative electrode comprising a negative electrode active material comprising a silicon material and an electrolyte solution comprising an electrolyte solvent comprising an open chain sulfone compound, a fluorinated cyclic carbonate and an open chain carbonate and a supporting salt comprising LiN(FSO2)2.
    Type: Application
    Filed: May 17, 2018
    Publication date: May 28, 2020
    Applicant: NEC CORPORATION
    Inventors: Ikiko SHIMANUKI, Takehiro NOGUCHI, Daisuke KAWASAKI, Takuya HASEGAWA
  • Patent number: 10644347
    Abstract: A negative electrode active material constituting a lithium ion secondary battery having high energy density and excellent cycle characteristics, and a negative electrode and a lithium ion secondary battery comprising the same are provided. The present invention relates to a negative electrode active material comprising graphite particles and crystalline silicon particles, wherein a median diameter of the crystalline silicon particles is 0.7 ?m or less, and a weight ratio of the crystalline silicon particles to the total weight of the graphite particles and the crystalline silicon particles is 1 wt % or more and 25 wt % or less.
    Type: Grant
    Filed: February 22, 2017
    Date of Patent: May 5, 2020
    Assignee: NEC Corporation
    Inventors: Daisuke Kawasaki, Takashi Ohtsuka, Suguru Tamai, Noboru Yoshida, Shinya Sudo
  • Publication number: 20200091559
    Abstract: A lithium ion secondary battery having high energy density and being excellent in cycle characteristics is provided. The present invention relates to a lithium ion secondary battery comprising: a negative electrode active material comprising a material comprising silicon as a constituent element; and an electrolyte solution comprising: a non-aqueous solvent comprising a fluorinated ether compound, an open-chain sulfone compound, and a cyclic carbonate compound, and a supporting salt comprising LiPF6, lithium bis(fluorosulfonyl)imide, and lithium bis(oxalato)borate (LiBOB); wherein the content of LiBOB in the electrolyte solution is 0.2 mass % or more.
    Type: Application
    Filed: May 23, 2018
    Publication date: March 19, 2020
    Applicant: NEC Corporation
    Inventors: Takehiro NOGUCHI, Takuya HASEGAWA, Ikiko SHIMANUKI, Daisuke KAWASAKI
  • Publication number: 20190393554
    Abstract: A purpose of one embodiment of the present invention is to provide a lithium ion secondary battery that has improved life-span characteristics. The first lithium ion secondary battery of the present invention comprises an electrolyte solution comprising a sulfone compound, a fluorinated ether compound and LiN(FSO2)2, and a negative electrode comprising a silicon material, wherein a content of LiN(FSO2)2 in the electrolyte solution is more than 5 weight % and 20 weight % or less.
    Type: Application
    Filed: November 30, 2017
    Publication date: December 26, 2019
    Applicant: NEC Corporation
    Inventors: Takehiro NOGUCHI, Takuya HASEGAWA, Daisuke KAWASAKI, lkiko SHIMANUKI
  • Patent number: 10454254
    Abstract: An uninterruptible power supply includes an input switch, an input filter, and a power converter disposed in this order, an output filter and an output switch disposed in this order from the power converter, and a plurality of conductors that connects the input switch, the input filter, the power converter, the output filter, and the output switch to each other in this order.
    Type: Grant
    Filed: July 4, 2017
    Date of Patent: October 22, 2019
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Seiitsu Kin, Daisuke Kawasaki, Yoshihiko Yamagata, Hiroki Muratsu, Tomo Kurozaki, Yosuke Iwamaru, Keita Koshii
  • Patent number: 10333174
    Abstract: The present invention relates to a lithium ion secondary battery comprising a positive electrode having a coating amount per unit area of 50 mg/cm2 or more and an electrode density of 3.3 g/cc or more and a negative electrode having a coating amount per unit area of 24 mg/cm2 or more and an electrode density of 1.5 g/cc or more, a separator having a shrinking ratio of 2% or less by heat treatment at 80° C. for 6 hours, and an electrolyte solution comprising at least one sulfonic acid ester compound, and a ratio of a sulfur content in the central portion (As) and a sulfur content in the edge portion (Bs) of the positive electrode and the negative electrode, in each, is 0.7?As/Bs?1.1.
    Type: Grant
    Filed: March 22, 2016
    Date of Patent: June 25, 2019
    Assignee: NEC Corporation
    Inventors: Daisuke Kawasaki, Kenichi Shimura, Noboru Yoshida, Kazuhiko Inoue, Jiro Iriyama
  • Publication number: 20190190312
    Abstract: In an uninterruptible power supply, first connection members that connect input side-switches of a plurality of uninterruptible power supply modules to each other and that connect output-side switches of the plurality of uninterruptible power supply modules to each other, and second connection members connected in parallel to the first connection members are disposed at positions accessible from a front side of the uninterruptible power supply modules.
    Type: Application
    Filed: July 4, 2017
    Publication date: June 20, 2019
    Inventors: Seiitsu KIN, Daisuke KAWASAKI, Yoshihiko YAMAGATA, Hiroki MURATSU, Tomo KUROZAKI, Yosuke IWAMARU, Keita KOSHII
  • Publication number: 20190173123
    Abstract: A lithium ion secondary battery having high energy density and excellent cycle characteristics is provided. The present invention relates to a lithium ion secondary battery comprising a negative electrode comprising a negative electrode active material comprising more than 25% by weight of a silicon alloy and a non-aqueous electrolyte solution comprising more than 10% by weight of a compound represented by LiN(SO2CnF2n+1)2 (wherein n is an integer of 0 or more) and 10% by weight or more of fluoroethylene carbonate (FEC).
    Type: Application
    Filed: May 23, 2017
    Publication date: June 6, 2019
    Applicant: NEC CORPORATION
    Inventors: Ikiko SHIMANUKI, Daisuke KAWASAKI, Hitoshi ISHIKAWA, Suguru TAMAI
  • Publication number: 20190165552
    Abstract: An uninterruptible power supply includes an input switch, an input filter, and a power converter disposed in this order, an output filter and an output switch disposed in this order from the power converter, and a plurality of conductors that connects the input switch, the input filter, the power converter, the output filter, and the output switch to each other in this order.
    Type: Application
    Filed: July 4, 2017
    Publication date: May 30, 2019
    Inventors: Seiitsu KIN, Daisuke KAWASAKI, Yoshihiko YAMAGATA, Hiroki MURATSU, Tomo KUROZAKI, Yosuke IWAMARU, Keita KOSHII
  • Patent number: 10290894
    Abstract: An exemplary embodiment of the present invention is a secondary battery which comprises a negative electrode and a battery electrolyte liquid comprising a supporting salt and a non-aqueous electrolyte solvent; wherein the negative electrode is obtained by pre-forming a SEI coating film on a negative electrode structure which is formed by binding a negative electrode active substance comprising a metal (a). that can be alloyed with lithium, a metal oxide (b) that can absorb and desorb lithium ion and a carbon material (c) that can absorb and desorb lithium ion, to a negative electrode current collector with a negative electrode binder, and wherein the non-aqueous electrolyte solvent contains at least an ionic liquid.
    Type: Grant
    Filed: June 23, 2011
    Date of Patent: May 14, 2019
    Assignee: NEC CORPORATION
    Inventors: Kazuaki Matsumoto, Daisuke Kawasaki, Masahiro Suguro, Midori Shimura, Yoko Hashizume
  • Patent number: 10224568
    Abstract: It is an object of the present invention to provide an electrolytic solution capable of suppressing gas generation. The present exemplary embodiment is an electrolytic solution comprising a supporting salt, a nonaqueous solvent that dissolves the supporting salt, a cyclic sulfonic acid ester compound represented by predetermined formula (1), and an acid anhydride. According to the exemplary embodiment, an electrolytic solution capable of suppressing gas generation can be provided.
    Type: Grant
    Filed: July 11, 2014
    Date of Patent: March 5, 2019
    Assignee: NEC Corporation
    Inventors: Noboru Yoshida, Shinsaku Saitho, Kazuaki Matsumoto, Ikiko Shimanuki, Daisuke Kawasaki, Yuukou Katou, Hitoshi Ishikawa
  • Publication number: 20190051928
    Abstract: A negative electrode active material constituting a lithium ion secondary battery having high energy density and excellent cycle characteristics, and a negative electrode and a lithium ion secondary battery comprising the same are provided. The present invention relates to a negative electrode active material comprising graphite particles and crystalline silicon particles, wherein a median diameter of the crystalline silicon particles is 0.7 ?m or less, and a weight ratio of the crystalline silicon particles to the total weight of the graphite particles and the crystalline silicon particles is 1 wt % or more and 25 wt % or less.
    Type: Application
    Filed: February 22, 2017
    Publication date: February 14, 2019
    Inventors: Daisuke KAWASAKI, Takashi OHTSUKA, Suguru TAMAI, Noboru YOSHIDA, Shinya SUDO