Patents by Inventor Yutaka Bannai

Yutaka Bannai 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: 8435672
    Abstract: The invention provides a lithium ion secondary battery comprising a positive electrode, a negative electrode and an electrolysis solution containing an aprotic solvent having an electrolyte dissolved in it, wherein the negative electrodes uses an amorphous carbon material as a negative electrode active material. The amorphous carbon material has (A) an average particle diameter (median size) of 7 ?m to 20 ?m inclusive as measured by a laser diffraction scattering method and (B) a particle size distribution as measured by a laser diffraction scattering method, in which distribution the ratio of particles of less than 3 ?m in diameter is 1% by mass to 10% mass inclusive, and is free of an electrical conducting material.
    Type: Grant
    Filed: April 19, 2007
    Date of Patent: May 7, 2013
    Assignee: NEC Energy Devices, Ltd.
    Inventors: Yutaka Bannai, Tatsuji Numata, Ryuichi Kasahara
  • Publication number: 20110318637
    Abstract: An objective of the present invention is to provide a lithium secondary battery which can achieve a higher capacity and a longer life without reduction in a lower voltage in the battery. In the present invention, a compound represented by general formula (I) described below is used as a cathode active material, and a compound represented by general formula (II) described below is used as an anode active material; Lia1(Nix1Mn2-x1-y1M1y1)O4??(I) wherein the M1 is at least one of Ti, Si, Mg and Al, the a1 satisfies 0?a1?1, the x1 satisfies 0.4?x1?0.6, and the y1 satisfies 0?y1?0.4; and Lia2M21-y2M3y2Oz2??(II) wherein the M2 is at least one of Si and Sn; the M3 is at least one of Fe, Ni and Cu, the a2 satisfies 0?a2?5, the y2 satisfies 0?y2<0.3, and the z2 satisfies 0<z2<2.
    Type: Application
    Filed: September 2, 2011
    Publication date: December 29, 2011
    Applicant: NEC TOKIN CORPORATION
    Inventors: Takehiro Noguchi, Masaaki Matsuu, Ryuichi Kasahara, Tatsuji Numata, Yutaka Bannai
  • Patent number: 8034475
    Abstract: A secondary battery includes an anode for a secondary battery, a cathode which absorbs and discharges lithium ions, and an electrolyte which is placed between the anode for the secondary battery and the cathode. The anode for the secondary battery includes an anode active material layer which absorbs and discharges lithium ions, the anode active material layer including a first layer including carbon as a chief ingredient, and a second layer including at least one first element having a theoretical capacity greater than a theoretical capacity of graphite, and at least one second element which has a theoretical capacity equal to or less than the theoretical capacity of graphite. The second layer includes particles, and the particles include the first element and the second element.
    Type: Grant
    Filed: June 7, 2010
    Date of Patent: October 11, 2011
    Assignee: NEC Corporation
    Inventors: Hironori Yamamoto, Yutaka Bannai, Mariko Miyachi, Jiro Iriyama, Hidemasa Kawai, Masato Shirakata
  • Publication number: 20100248031
    Abstract: A secondary battery includes an anode for a secondary battery, a cathode which absorbs and discharges lithium ions, and an electrolyte which is placed between the anode for the secondary battery and the cathode. The anode for the secondary battery includes an anode active material layer which absorbs and discharges lithium ions, the anode active material layer including a first layer including carbon as a chief ingredient, and a second layer including at least one first element having a theoretical capacity greater than a theoretical capacity of graphite, and at least one second element which has a theoretical capacity equal to or less than the theoretical capacity of graphite. The second layer includes particles, and the particles include the first element and the second element.
    Type: Application
    Filed: June 7, 2010
    Publication date: September 30, 2010
    Applicant: NEC Corporation
    Inventors: Hironori Yamamoto, Yutaka Bannai, Mariko Miyachi, Jiro Iriyama, Hidemasa Kawai, Masato Shirakata
  • Patent number: 7763387
    Abstract: Since a first layer (a carbon layer 2a) whose chief ingredient is carbon and a second layer (Li absorbing layer 3a) containing particles having a theoretical capacity greater than that of graphite are formed on anode collector 1a, high capacity and high operation voltage can be realized. Since a element having a theoretical capacity equal to or less than that of graphite is added to the particles constituting this second layer, expansion and contraction of volume according to the charge and discharge are suppressed. This enables capacity deterioration to be suppressed even though cycles go on.
    Type: Grant
    Filed: May 22, 2003
    Date of Patent: July 27, 2010
    Assignee: NEC Corporation
    Inventors: Hironori Yamamoto, Yutaka Bannai, Mariko Miyachi, Jiro Iriyama, Hidemasa Kawai, Masato Shirakata
  • Publication number: 20100173201
    Abstract: An objective of the present invention is to provide a lithium secondary battery which can achieve a higher capacity and a longer life without reduction in a lower voltage in the battery. In the present invention, a compound represented by general formula (I) described below is used as a cathode active material, and a compound represented by general formula (II) described below is used as an anode active material; Lia1(Nix1Mn2-x1-y1M1y1)O4??(I) wherein the M1 is at least one of Ti, Si, Mg and Al, the a1 satisfies 0?a1?1, the x1 satisfies 0.4?x1?0.6, and the y1 satisfies 0?y1?0.4; and Lia2M21-y2M3y2Oz2??(II) wherein the M2 is at least one of Si and Sn; the M3 is at least one of Fe, Ni and Cu, the a2 satisfies 0?a2?5, the y2 satisfies 0?y2<0.3, and the z2 satisfies 0<z2<2.
    Type: Application
    Filed: March 17, 2010
    Publication date: July 8, 2010
    Applicant: NEC TOKIN CORPORATION
    Inventors: Takehiro NOGUCHI, Masaaki MATSUU, Ryuichi KASAHARA, Tatsuji NUMATA, Yutaka BANNAI
  • Publication number: 20100173200
    Abstract: An objective of the present invention is to provide a lithium secondary battery which can achieve a higher capacity and a longer life without reduction in a lower voltage in the battery. In the present invention, a compound represented by general formula (I) described below is used as a cathode active material, and a compound represented by general formula (II) described below is used as an anode active material; Lia1(Nix1Mn2-x1-y1M1y1)O4??(I) wherein the M1 is at least one of Ti, Si, Mg and Al, the a1 satisfies 0?a1?1, the x1 satisfies 0.4?x1?0.6, and the y1 satisfies 0?y1?0.4; and Lia2M21-y2M3y2Oz2??(II) wherein the M2 is at least one of Si and Sn; the M3 is at least one of Fe, Ni and Cu, the a2 satisfies 0?a2?5, the y2 satisfies 0?y2?0.3, and the z2 satisfies 0?z2?2.
    Type: Application
    Filed: March 17, 2010
    Publication date: July 8, 2010
    Applicant: NEC TOKIN CORPORATION
    Inventors: Takehiro NOGUCHI, Masaaki MATSUU, Ryuichi KASAHARA, Tatsuji NUMATA, Yutaka BANNAI
  • Patent number: 7642011
    Abstract: A radical compound may be used as an active material for an anode layer 2 to provide a novel stable secondary battery with a higher energy density and a larger capacity. The radical compound used has, for example, a spin concentration of 1021 spins/g or more.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: January 5, 2010
    Assignee: NEC Corporation
    Inventors: Kentaro Nakahara, Masaharu Satoh, Shigeyuki Iwasa, Hiroshi Yageta, Yutaka Bannai, Yukiko Morioka, Etsuo Hasegawa
  • Patent number: 7462244
    Abstract: A vacuum deposition apparatus is used for deposit evaporated substance from evaporation sources (6a and 6b) on the desired position of a flexible substrate (1). While the flexible substrate (1) is carried using rollers in a vacuum, shutters (8a and 8b) are opened and closed to control the movement of the evaporated substance via openings. A film having a desired shape of pattern is formed on the flexible substrate (1) with higher controllability.
    Type: Grant
    Filed: November 21, 2002
    Date of Patent: December 9, 2008
    Assignee: NEC Corporation
    Inventors: Koji Utsugi, Hironori Yamamoto, Mariko Miyachi, Tamaki Miura, Mitsuhiro Mori, Yutaka Bannai, Ikiko Yamazaki
  • Publication number: 20070248885
    Abstract: The invention provides a lithium ion secondary battery comprising a positive electrode, a negative electrode and an electrolysis solution containing an aprotic solvent having an electrolyte dissolved in it, wherein the negative electrodes uses an amorphous carbon material as a negative electrode active material. The amorphous carbon material has (A) an average particle diameter (median size of 7 ?m to 20 ?m inclusive as measured by a laser diffraction scattering method and (B) a particle size distribution as measured by a laser diffraction scattering method, in which distribution the ratio of particles of less than 3 ?m in diameter is 1% by mass to 10% mass inclusive, and is free of an electrical conducting material.
    Type: Application
    Filed: April 19, 2007
    Publication date: October 25, 2007
    Applicant: NEC TOKIN Corporation
    Inventors: Yutaka Bannai, Tatsuji Numata, Ryuichi Kasahara
  • Patent number: 7285359
    Abstract: An object of the present invention is to provide a negative electrode for a secondary battery which has large capacity and restrains a rise in resistance inside the battery and reduction in capacity even after cycles and the secondary battery using the same. A first active material layer 2a comprising members occluding and releasing Li onto a collector 1a is formed and a second active material layer 3a as an alloy layer containing metal forming alloy with lithium or lithium and metal not-forming alloy with lithium is formed thereon. The secondary battery is constituted using the negative electrode.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: October 23, 2007
    Assignee: NEC Corporation
    Inventors: Hironori Yamamoto, Mitsuhiro Mori, Jiro Iriyama, Mariko Miyachi, Koji Utsugi, Yutaka Bannai, Tamaki Miura, Ikiko Yamazaki
  • Publication number: 20070172734
    Abstract: An objective of the present invention is to provide a lithium secondary battery which can achieve a higher capacity and a longer life without reduction in a lower voltage in the battery. In the present invention, a compound represented by general formula (I) described below is used as a cathode active material, and a compound represented by general formula (II) described below is used as an anode active material; Lia1(Nix1Mn2-x1-y1M1y1)O4??(I) wherein the M1 is at least one of Ti, Si, Mg and Al, the a1 satisfies 0<a1<, the x1 satisfies 0.4?x1?0.6, and the y1 satisfies 0?y1?0.4; and Lia2M21-y2M3y2Oz2??(II) wherein the M2 is at least one of Si and Sn; the M3 is at least one of Fe, Ni and Cu, the a2 satisfies 0?a2?5, the y2 satisfies 0?y2<0.3, and the z2 satisfies 0<z2<2.
    Type: Application
    Filed: January 24, 2007
    Publication date: July 26, 2007
    Inventors: Takehiro NOGUCHI, Masaaki MATSUU, Ryuichi KASAHARA, Tatsuji NUMATA, Yutaka BANNAI
  • Patent number: 7118831
    Abstract: An anode with a multi-layer structure including a first layer (21) having carbon as a main component, and a second layer (22) having lithium-ion conductivity and including a material as a main component thereof which can insert and extract lithium ions, or a multi-layer structure including a third layer (23) containing lithium in addition to the first layer and the second layer, and a lithium secondary battery including the same. The lithium secondary battery can be provided in which the battery capacity is substantially enhanced in the voltage range where the battery is actually used while maintaining the higher charge-discharge efficiency and the excellent cycle performance.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: October 10, 2006
    Assignee: NEC Corporation
    Inventors: Yutaka Bannai, Hironori Yamamoto, Mariko Miyachi, Ikiko Yamazaki, Koji Utsugi, Jiro Iriyama, Tamaki Miura, Mitsuhiro Mori, Hidemasa Kawai
  • Patent number: 7045248
    Abstract: In a secondary battery comprising a positive electrode, a negative electrode and an electrolyte therebetween, active material of one of the positive electrode and the negative electrode includes a compound having boron radicals or sulfur radicals.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: May 16, 2006
    Assignee: NEC Corporation
    Inventors: Yutaka Bannai, Kentaro Nakahara, Yukiko Morioka, Shigeyuki Iwasa, Masaharu Satoh
  • Publication number: 20050170247
    Abstract: A radical compound may be used as an active material for an anode layer 2 to provide a novel stable secondary battery with a higher energy density and a larger capacity. The radical compound used has, for example, a spin concentration of 1021 spins/g or more.
    Type: Application
    Filed: February 25, 2005
    Publication date: August 4, 2005
    Applicant: NEC CORPORATION
    Inventors: Kentaro Nakahara, Masaharu Satoh, Shigeyuki Iwasa, Hiroshi Yageta, Yutaka Bannai, Yukiko Morioka, Etsuo Hasegawa
  • Publication number: 20050147888
    Abstract: An object of the present invention is to provide a negative electrode for a secondary battery which has large capacity and restrains a rise in resistance inside the battery and reduction in capacity even after cycles and the secondary battery using the same. A first active material layer 2a comprising members occluding and releasing Li onto a collector 1a is formed and a second active material layer 3a as an alloy layer containing metal forming alloy with lithium or lithium and metal not-forming alloy with lithium is formed thereon. The secondary battery is constituted using the negative electrode.
    Type: Application
    Filed: January 22, 2003
    Publication date: July 7, 2005
    Inventors: Hironori Yamamoto, Mitsuhiro Mori, Jiro Iriyama, Mariko Miyachi, Koji Utsugi, Yutaka Bannai, Tamaki Miura, Ikiko Yamazaki
  • Patent number: 6893775
    Abstract: A battery includes active material containing neutral carbon radical compound at one of or both of the electrodes, and the neutral carbon radicals participate in electrode reaction for generating current; the battery is light, because any heavy metal is not required for the active material, and the battery achieves large capacity without sacrifice of stability, because the unpaired electrons are localized at the carbon atoms in the neutral carbon radical compound.
    Type: Grant
    Filed: October 4, 2001
    Date of Patent: May 17, 2005
    Assignee: NEC Corporation
    Inventors: Yukiko Morioka, Masaharu Satoh, Shigeyuki Iwasa, Yutaka Bannai, Kentaro Nakahara
  • Publication number: 20050089757
    Abstract: An anode with a multi-layer structure including a first layer (21) having carbon as a main component, and a second layer (22) having lithium-ion conductivity and including a material as a main component thereof which can insert and extract lithium ions, or a multi-layer structure including a third layer (23) containing lithium in addition to the first layer and the second layer, and a lithium secondary battery including the same. The lithium secondary battery can be provided in which the battery capacity is substantially enhanced in the voltage range where the battery is actually used while maintaining the higher charge-discharge efficiency and the excellent cycle performance.
    Type: Application
    Filed: April 9, 2003
    Publication date: April 28, 2005
    Inventors: Yutaka Bannai, Hironori Yamamoto, Mariko Miyachi, Ikiko Yamazaki, Koji Utsugi, Jiro Iriyama, Tamaki Miura, Mitsuhiro Mori, Hidemasa Kawai
  • Publication number: 20050084759
    Abstract: A lithium ion secondary battery provided with both high weight energy density and good cycle characteristics (capacity retaining ratio during an extended use). A secondary battery comprising a negative electrode having, as a negative electrode active material, carbon and a lithium absorbing material that forms an alloy with lithium, the above active material having a layer structure, a positive electrode capable of absorbing and desorbing lithium ions, and an electrolyte disposed between the positive and negative electrodes, wherein the Li content in the lithium absorbing material layer in the negative electrode is between 31 and 67% at a discharge depth of 100%.
    Type: Application
    Filed: December 26, 2002
    Publication date: April 21, 2005
    Inventors: Mariko Miyachi, Jiro Iriyama, Ikiko Yamazaki, Hironori Yamamoto, Koji Utsugi, Tamaki Miura, Mitsuhiro Mori, Yutaka Bannai
  • Publication number: 20050084758
    Abstract: Since a first layer (a carbon layer 2a) whose chief ingredient is carbon and a second layer (Li absorbing layer 3a) containing particles having a theoretical capacity greater than that of graphite are formed on anode collector 1a, high capacity and high operation voltage can be realized. Since a element having a theoretical capacity equal to or less than that of graphite is added to the particles constituting this second layer, expansion and contraction of volume according to the charge and discharge are suppressed. This enables capacity deterioration to be suppressed even though cycles go on.
    Type: Application
    Filed: May 22, 2003
    Publication date: April 21, 2005
    Inventors: Hironori Yamamoto, Yutaka Bannai, Mariko Miyachi, Jiro Iriyama, Hidemasa Kawai, Masato Shirakata