Patents by Inventor Takanobu Kawai

Takanobu Kawai 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: 11276858
    Abstract: A negative electrode active material for a lithium ion secondary battery, made up of substantially spherical graphite particles (A), having fine protrusions on the surfaces thereof and obtained by impregnating and coating substantially spherical graphite particles with a mixture of pitch and carbon black, followed by baking in a range of 900 to 1500° C. In accordance with Raman spectroscopic analysis of the particles (A) using argon laser Raman scattering light, there exists a G-band composite peak comprising peaks in the vicinity of 1600 cm?1, and 1580 cm?1, respectively, and at least one peak in the vicinity of D-band at 1380 cm?1, an interlayer distance of the lattice plane d002, obtained by wide-range X-ray diffraction, being in the range of 0.335 to 0.337 nm.
    Type: Grant
    Filed: February 28, 2019
    Date of Patent: March 15, 2022
    Assignee: NIPPON CARBON CO., LTD.
    Inventors: Takanobu Kawai, Ken-ichi Hongawa, Hayato Matsumoto, Kazuaki Yamashita
  • Publication number: 20190198875
    Abstract: A negative electrode active material for a lithium ion secondary battery, made up of substantially spherical graphite particles (A), having fine protrusions on the surfaces thereof and obtained by impregnating and coating substantially spherical graphite particles with a mixture of pitch and carbon black, followed by baking in a range of 900 to 1500° C. In accordance with Raman spectroscopic analysis of the particles (A) using argon laser Raman scattering light, there exists a G-band composite peak comprising peaks in the vicinity of 1600 cm?1, and 1580 cm?1, respectively, and at least one peak in the vicinity of D-band at 1380 cm?1, an interlayer distance of the lattice plane d002, obtained by wide-range X-ray diffraction, being in the range of 0.335 to 0.337 nm.
    Type: Application
    Filed: February 28, 2019
    Publication date: June 27, 2019
    Inventors: Takanobu KAWAI, Ken-ichi HONGAWA, Hayato MATSUMOTO, Kazuaki YAMASHITA
  • Patent number: 10283775
    Abstract: A negative electrode active material for a lithium ion secondary battery, made up of substantially spherical graphite particles (A), having fine protrusions on the surfaces thereof and obtained by impregnating and coating substantially spherical graphite particles with a mixture of pitch and carbon black, followed by baking in a range of 900 to 1500° C. In accordance with Raman spectroscopic analysis of the particles (A) using argon laser Raman scattering light, there exists a G-band composite peak comprising peaks in the vicinity of 1600 cm?1, and 1580 cm?1, respectively, and at least one peak in the vicinity of D-band at 1380 cm?1, an interlayer distance of the lattice plane d002, obtained by wide-range X-ray diffraction, being in the range of 0.335 to 0.337 nm.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: May 7, 2019
    Assignee: NIPPON CARBON CO., LTD.
    Inventors: Takanobu Kawai, Ken-ichi Hongawa, Hayato Matsumoto, Kazuaki Yamashita
  • Publication number: 20170084921
    Abstract: A negative electrode active material for a lithium ion secondary battery, made up of substantially spherical graphite particles (A), having fine protrusions on the surfaces thereof and obtained by impregnating and coating substantially spherical graphite particles with a mixture of pitch and carbon black, followed by baking in a range of 900 to 1500° C. In accordance with Raman spectroscopic analysis of the particles (A) using argon laser Raman scattering light, there exists a G-band composite peak comprising peaks in the vicinity of 1600 cm?1, and 1580 cm?1, respectively, and at least one peak in the vicinity of D-band at 1380 cm?1, an interlayer distance of the lattice plane d002, obtained by wide-range X-ray diffraction, being in the range of 0.335 to 0.337 nm.
    Type: Application
    Filed: October 21, 2016
    Publication date: March 23, 2017
    Inventors: Takanobu KAWAI, Ken-ichi HONGAWA, Hayato MATSUMOTO, Kazuaki YAMASHITA
  • Patent number: 9490499
    Abstract: A negative electrode active material for a lithium ion secondary battery, made up of substantially spherical graphite particles (A), having fine protrusions on the surfaces thereof and obtained by impregnating and coating substantially spherical graphite particles with a mixture of pitch and carbon black, followed by baking in a range of 900 to 1500° C. In accordance with Raman spectroscopic analysis of the particles (A) using argon laser Raman scattering light, there exists a G-band composite peak comprising peaks in the vicinity of 1600 cm?1, and 1580 cm?1, respectively, and at least one peak in the vicinity of D-band at 1380 cm?1, an interlayer distance of the lattice plane d002, obtained by wide-range X-ray diffraction, being in the range of 0.335 to 0.337 nm.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: November 8, 2016
    Assignee: NIPPON CARBON CO., LTD.
    Inventors: Takanobu Kawai, Ken-ichi Hongawa, Hayato Matsumoto, Kazuaki Yamashita
  • Patent number: 8728668
    Abstract: A negative electrode active material for a lithium ion rechargeable battery having high electrode density, excellent in permeability of an electrolyte, less in capacity loss due to charging/discharging, and excellent in cycle performance is provided at a low cost. The negative electrode active material is a mixture of three kinds of graphite powders having different hardnesses and shapes from one another, with a binder added thereto and is coated onto a metallic current collector to be dried and pressed, thereby rendering an electrode density not lower than 1.7 g/cm3.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: May 20, 2014
    Assignee: Nippon Carbon Co., Ltd.
    Inventors: Takanobu Kawai, Kenichi Hongawa, Hayato Matsumoto
  • Publication number: 20100297500
    Abstract: A negative electrode active material for a lithium ion rechargeable battery having high electrode density, excellent in permeability of an electrolyte, less in capacity loss due to charging/discharging, and excellent in cycle performance is provided at a low cost. Further, there is provided a negative electrode for the lithium ion rechargeable battery, wherein the negative electrode active material as a mixture of three kinds of graphite powders, different in hardness and shape from one another, with a binder added thereto, is coated onto a metallic current collector to be dried and pressed, thereby rendering an electrode density not lower than 1.7 g/cm3. In terms of relationship between press pressure P(kN), and electrode density D(g/cm3), the negative electrode active material was composed of graphite powder A (D=0.04 to 0.06 P), graphite powder B (D=0.04 to 0.06 P), and graphite powder C (D=0.01 to 0.
    Type: Application
    Filed: May 25, 2007
    Publication date: November 25, 2010
    Inventors: Takanobu Kawai, Kenichi Hongawa, Hayato Matsumoto
  • Publication number: 20090311599
    Abstract: There is provided a negative electrode for a lithium ion secondary battery high in discharge capacity per unit volume, small in capacity loss at the time of initial charge/discharge, and excellent in rapid charge/discharge characteristics. Natural graphite, rendered spherical in shape, is mixed with carbon black, and pitch is added to a mixture thus formed to be thermally kneaded before baked at a temperature in a range of 900 to 1500° C., thereby obtaining graphite particles (A), each being substantially spherical in shape, and having fine protrusions on the surface thereof. Since the graphite particles (A) have the fine protrusions on the surface thereof, a multitude of electrically conducting networks are built in a complex way within an electrode, the graphite particles (A) can serve as a negative electrode material excellent in rapid charge/discharge characteristics, and power characteristics. The graphite particles (A) further baked at 3000° C.
    Type: Application
    Filed: July 6, 2007
    Publication date: December 17, 2009
    Inventors: Takanobu Kawai, Ken-ichi Hongawa, Hayato Matsumoto, Kazuaki Yamashita
  • Patent number: 5447624
    Abstract: A microspherical packing for liquid chromatography, which comprises a porous silicon carbide having numerous through-pores, and a process for producing said microspherical packing.
    Type: Grant
    Filed: April 6, 1994
    Date of Patent: September 5, 1995
    Assignees: Nippon Carbon Co., Ltd., Tosoh Corporation
    Inventors: Takanobu Kawai, Hiroshi Wakizaka, Hiroyuki Moriyama, Katsuo Komiya, Hiroshi Ichikawa, Akira Yokoyama
  • Patent number: 5270280
    Abstract: A packing material for liquid chromatography is produced by mixing 1.0 part by weight of carbon black, 0.5 to 2.5 parts by weight of one or a mixture of a synthetic resin which can be graphitized by heating and a toluene- or benzene-soluble component of pitches, and an organic solvent to obtain a mixture. The carbon black has a particle diameter of 12 to 40 nm, a specific surface area of 50 to 650 m.sup.2 /g, a DBP oil absorption amount of 50 to 150 ml/100 g. The synthetic resin is one selected from phenol resin, furan resin, furfural resin, divinylbenzene resin and urea resin. The pitches are ones selected from petroleum pitches, coal-tar pitches and liquefied coal oil. The mixture is granulated by spray granulation or emulsion granulation to obtain granules whose ratio L.sub.min /L.sub.max of a minor axis diameter L.sub.min to a major axis diameter L.sub.max is 0.90 to 1.0. The heat treatment of the granules is also made in an inert gas under pressure.
    Type: Grant
    Filed: October 30, 1991
    Date of Patent: December 14, 1993
    Assignees: Nippon Carbon Co., Ltd., Tosoh Corporation
    Inventors: Hiroshi Ichikawa, Akira Yokoyama, Takanobu Kawai, Hiroyuki Moriyama, Katsuo Komiya, Yoshio Kato