Patents by Inventor Tsuyoshi Iijima

Tsuyoshi Iijima 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: 8785047
    Abstract: A lithium-ion secondary battery device comprises a positive electrode collector having a surface formed with a positive electrode active material layer containing a positive electrode active material; a negative electrode collector having a surface formed with a negative electrode active material layer containing a negative electrode active material; an electrically insulating porous separator; and an electrolyte containing a lithium salt and being in contact with the positive electrode active material layer, negative electrode active material layer, and separator. The negative electrode active material is a carbon material having a graphite structure. The amount of the carbon material supported by the negative electrode active material layer is 2.0 to 4.0 mg/cm2. The graphite structure in an X-ray diffraction pattern of the carbon material exhibits a peak intensity P101 of (101) plane and a peak intensity P100 of (100) plane having a ratio (P101/P100) of 2.0 to 2.8 therebetween.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: July 22, 2014
    Assignee: TDK Corporation
    Inventors: Kazuya Ogawa, Tsuyoshi Iijima, Satoshi Maruyama
  • Patent number: 8257865
    Abstract: The positive electrode active material in accordance with the present invention is used for a positive electrode for a lithium-ion secondary battery, includes Li, Mn, Ni, Co, and O atoms, and has a substantially halite type crystal structure. Specifically, it is preferably expressed by LiaMnbNicCodOe, where a is 0.85 to 1.1, b is 0.2 to 0.6, c is 0.2 to 0.6, d is 0.1 to 0.5, and e is 1 to 2 (the sum of b, c, and d being 1). Because of such composition and crystal structure, the positive electrode active material of the present invention reduces the amount of elution of the battery into the liquid electrolyte and enhances the stability at a high temperature.
    Type: Grant
    Filed: August 7, 2008
    Date of Patent: September 4, 2012
    Assignee: TDK Corporation
    Inventors: Tadashi Suzuki, Kazuya Ogawa, Tsuyoshi Iijima, Satoshi Maruyama
  • Patent number: 8142927
    Abstract: A lithium secondary battery comprising positive and negative electrodes both capable of occluding and releasing lithium ions, and a lithium ion conductive material which contains a compound of formula (1) exhibits improved characteristics including charge/discharge efficiency, low-temperature properties and cycle performance when (a) only one substituent group of R1, R2, R3 and R4 in formula (1) is alkyl, (b) the negative electrode-constituting material partially contains a carboxyl or hydroxyl group-bearing compound, and the lithium ion conductive material contains propylene carbonate, or (c) a positive electrode active material is a lithium-containing transition metal compound, a negative electrode active material is a carbonaceous material, and the lithium ion conductive material contains as a non-aqueous electrolysis solution a solvent mixture of propylene carbonate and ethylene carbonate in combination with a chain-like carbonate as a low-viscosity solvent.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: March 27, 2012
    Assignee: TDK Corporation
    Inventors: Atushi Sano, Tsuyoshi Iijima, Satoshi Maruyama, Kazuya Ogawa
  • Patent number: 8114543
    Abstract: A lithium ion secondary battery, having a positive electrode, a negative electrode, and a separator provided between the positive electrode and the negative electrode, the positive electrode and the negative electrode each having a collector and an active material layer provided over the collector, and the relationship Ts?4Tc being satisfied, where Ts is the puncture strength of the separator, and Tc is the puncture strength of the collector of the positive electrode and/or the negative electrode.
    Type: Grant
    Filed: December 11, 2006
    Date of Patent: February 14, 2012
    Assignee: TDK Corporation
    Inventors: Atsushi Sano, Tsuyoshi Iijima
  • Patent number: 7709155
    Abstract: A nonaqueous solvent in a nonaqueous electrolytic solution in a lithium-ion secondary battery 1 contains propylene carbonate (PC), a first compound expressed by formula (I), and a second compound expressed by formula (II). The content of PC in the nonaqueous solvent is at least 10 volume %. The content X [mass %] of the first compound and the content Y [mass %] of the second compound simultaneously satisfy the conditions represented by expressions (1) and (2) [2?(X+Y)?8 (1), 0.01?(Y/X)?0.30 (2)]. R1 to R6 in formula (I) indicate any of a hydrogen atom and hydrocarbon groups having a carbon number of 1 to 3, whereas R7 and R8 in formula (II) indicate any of a hydrogen atom and hydrocarbon groups having a carbon number of 1 to 3.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: May 4, 2010
    Assignee: TDK Corporation
    Inventors: Kazuya Ogawa, Atsushi Sano, Tsuyoshi Iijima, Satoshi Maruyama
  • Patent number: 7651815
    Abstract: A lithium secondary battery comprising positive and negative electrodes both capable of occluding and releasing lithium ions, and a lithium ion conductive material which contains a compound of formula (1) exhibits improved characteristics including charge/discharge efficiency, low-temperature properties and cycle performance when (a) only one substituent group of R1, R2, R3 and R4 in formula (1) is alkyl, (b) the negative electrode-constituting material partially contains a carboxyl or hydroxyl group-bearing compound, and the lithium ion conductive material contains propylene carbonate, or (c) a positive electrode active material is a lithium-containing transition metal compound, a negative electrode active material is a carbonaceous material, and the lithium ion conductive material contains as a non-aqueous electrolysis solution a solvent mixture of propylene carbonate and ethylene carbonate in combination with a chain-like carbonate as a low-viscosity solvent
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: January 26, 2010
    Assignee: TDK Corporation
    Inventors: Atsushi Sano, Tsuyoshi Iijima, Satoshi Maruyama, Kazuya Ogawa
  • Patent number: 7651818
    Abstract: A lithium ion secondary battery having a positive electrode 3 which contains, as a positive electrode active material, a composite metal oxide containing at least one of Li, Co, Mn, and Ni as a metal component thereof; a negative electrode 2 which contains a negative electrode active material; and a nonaqueous electrolyte solution containing a lithium salt. A charging method is characterized in that constant-current charging is performed with use of a set charging current value of equal to or greater than 0.5C and less than 2C (ā€œCā€ referred to here is a rated capacity value of said lithium ion second battery).
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: January 26, 2010
    Assignee: TDK Corporation
    Inventors: Tsuyoshi Iijima, Kazuya Ogawa
  • Patent number: 7615084
    Abstract: A cathode, an anode and a porous film are first provided. Then, the cathode and anode are aligned with the porous film and a part of the cathode and a part of the anode are fixed to said porous film. Then, the cathode, anode and porous film are immersed in a liquid electrolyte. Finally, the cathode and anode are integrated with the porous film by compression. With this process, it is possible to produce a thin and lightweight polymer secondary battery or other secondary batteries with ease yet at low cost.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: November 10, 2009
    Assignee: TDK Corporation
    Inventors: Tsuyoshi Iijima, Toshinobu Miyakoshi, Satoshi Maruyama, Makoto Kobayashi
  • Patent number: 7583058
    Abstract: The method of charging a lithium ion secondary battery uses a lithium ion secondary battery comprising a positive electrode including a mixed metal oxide containing at least Li, Mn, and Ni as metal components as a positive electrode active material, a negative electrode, and a nonaqueous electrolytic solution containing a lithium salt; and includes a constant current charging step of carrying out constant current charging with a set charging current value I1 corresponding to a set value nC satisfying the condition represented by the expression of 2C?nC?60C, where C is a rated capacity value of the lithium ion secondary battery, and n is a number of 2 to 60.
    Type: Grant
    Filed: November 15, 2004
    Date of Patent: September 1, 2009
    Assignee: TDK Corporation
    Inventors: Tsuyoshi Iijima, Kazuya Ogawa, Toshifumi Tanaka, Satoshi Maruyama
  • Publication number: 20080314482
    Abstract: The positive electrode active material in accordance with the present invention is used for a positive electrode for a lithium-ion secondary battery, includes Li, Mn, Ni, Co, and O atoms, and has a substantially halite type crystal structure. Specifically, it is preferably expressed by LiaMnbNicCodOe, where a is 0.85 to 1.1, b is 0.2 to 0.6, c is 0.2 to 0.6, d is 0.1 to 0.5, and e is 1 to 2 (the sum of b, c, and d being 1). Because of such composition and crystal structure, the positive electrode active material of the present invention reduces the amount of elution of the battery into the liquid electrolyte and enhances the stability at a high temperature.
    Type: Application
    Filed: August 7, 2008
    Publication date: December 25, 2008
    Applicant: TDK Corporation
    Inventors: Tadashi Suzuki, Kazuya Ogawa, Tsuyoshi Iijima, Satoshi Maruyama
  • Patent number: 7413829
    Abstract: In a lithium secondary battery comprising positive and negative electrodes each comprising at least an active material capable of occluding and releasing lithium ions, a binder and a current collector, and an electrolytic solution, the active material in the positive and/or negative electrode has been made conductive by coating its surface with a conductive agent and a binder, and affixed to the surface of the collector by a dry process. The lithium secondary battery is given a higher energy density and a higher output density and will find a wider range of application.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: August 19, 2008
    Assignee: TDK Corporation
    Inventors: Tadashi Suzuki, Tsuyoshi Iijima, Jun-ichi Satoh, Satoshi Maruyama
  • Publication number: 20080014497
    Abstract: A lithium secondary battery comprising positive and negative electrodes both capable of occluding and releasing lithium ions, and a lithium ion conductive material which contains a compound of formula (1) exhibits improved characteristics including charge/discharge efficiency, low-temperature properties and cycle performance when (a) only one substituent group of R1, R2, R3 and R4 in formula (1) is alkyl, (b) the negative electrode-constituting material partially contains a carboxyl or hydroxyl group-bearing compound, and the lithium ion conductive material contains propylene carbonate, or (c) a positive electrode active material is a lithium-containing transition metal compound, a negative electrode active material is a carbonaceous material, and the lithium ion conductive material contains as a non-aqueous electrolysis solution a solvent mixture of propylene carbonate and ethylene carbonate in combination with a chain-like carbonate as a low-viscosity solvent.
    Type: Application
    Filed: September 20, 2007
    Publication date: January 17, 2008
    Applicant: TDK CORPORATION
    Inventors: Atsushi Sano, Tsuyoshi Iijima, Satoshi Maruyama, Kazuya Ogawa
  • Publication number: 20070134556
    Abstract: A lithium ion secondary battery, having a positive electrode, a negative electrode, and a separator provided between the positive electrode and the negative electrode, the positive electrode and the negative electrode each having a collector and an active material layer provided over the collector, and the relationship Ts?4Tc being satisfied, where Ts is the puncture strength of the separator, and Tc is the puncture strength of the collector of the positive electrode and/or the negative electrode.
    Type: Application
    Filed: December 11, 2006
    Publication date: June 14, 2007
    Applicant: TDK CORPORATION
    Inventors: Atsushi Sano, Tsuyoshi Iijima
  • Publication number: 20070122714
    Abstract: In a lithium secondary battery comprising positive and negative electrodes each comprising at least an active material capable of occluding and releasing lithium ions, a binder and a current collector, and an electrolytic solution, the active material in the positive and/or negative electrode has been made conductive by coating its surface with a conductive agent and a binder, and affixed to the surface of the collector by a dry process. The lithium secondary battery is given a higher energy density and a higher output density and will find a wider range of application.
    Type: Application
    Filed: January 31, 2007
    Publication date: May 31, 2007
    Applicant: TDK CORPORATION
    Inventors: Tadashi SUZUKI, Tsuyoshi Iijima, Jun-ichi Satoh, Satoshi Maruyama
  • Patent number: 7195844
    Abstract: In a lithium secondary battery comprising positive and negative electrodes each comprising at least an active material capable of occluding and releasing lithium ions, a binder and a current collector, and an electrolytic solution, the active material in the positive and/or negative electrode has been made conductive by coating its surface with a conductive agent and a binder, and affixed to the surface of the collector by a dry process. The lithium secondary battery is given a higher energy density and a higher output density and will find a wider range of application.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: March 27, 2007
    Assignee: TDK Corporation
    Inventors: Tadashi Suzuki, Tsuyoshi Iijima, Jun-ichi Satoh, Satoshi Maruyama
  • Patent number: 7189478
    Abstract: The invention aims to provide a lithium secondary battery exhibiting the improved function of self safety in an abnormal state without sacrificing battery characteristics. To attain the object, in a lithium secondary battery comprising a positive electrode (3a, 3b), a negative electrode (2a, 2b), an electrolytic solution, and a separator, a plurality of positive electrodes (3a, 3b) and negative electrodes (2a, 2b) are arranged to construct an electrode structure which includes an outermost layer of electrode on which a back coat layer (11) is formed.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: March 13, 2007
    Assignee: TDK Corporation
    Inventors: Tsuyoshi Iijima, Atsushi Sano, Satoshi Maruyama
  • Publication number: 20070037049
    Abstract: An auxiliary power unit of the present invention has an auxiliary lithium-ion secondary battery, a charge connector connected to the auxiliary lithium-ion secondary battery and adapted to receive power from an external charger, and a supply connector connected to the auxiliary lithium-ion secondary battery and adapted to supply power of the auxiliary lithium-ion secondary battery to an external portable device, and the auxiliary lithium-ion secondary battery is constructed so that each of thicknesses of cathode active material and anode active material layers is in the range of 10 to 40 ?m.
    Type: Application
    Filed: August 8, 2006
    Publication date: February 15, 2007
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi Iijima, Kazuya Ogawa
  • Publication number: 20070015063
    Abstract: A nonaqueous solvent in a nonaqueous electrolytic solution in a lithium-ion secondary battery 1 contains propylene carbonate (PC), a first compound expressed by formula (I), and a second compound expressed by formula (II). The content of PC in the nonaqueous solvent is at least 10 volume %. The content X [mass %] of the first compound and the content Y [mass %] of the second compound simultaneously satisfy the conditions represented by expressions (1) and (2) [2?(X+Y)?8 (1), 0.01?(Y/X)?0.30 (2)]. R1 to R6 in formula (I) indicate any of a hydrogen atom and hydrocarbon groups having a carbon number of 1 to 3, whereas R7 and R8 in formula (II) indicate any of a hydrogen atom and hydrocarbon groups having a carbon number of 1 to 3.
    Type: Application
    Filed: May 28, 2004
    Publication date: January 18, 2007
    Applicant: TDK Corporation
    Inventors: Kazuya Ogawa, Atsushi Sano, Tsuyoshi Iijima, Satoshi Maruyama
  • Publication number: 20060197496
    Abstract: A combination of lithium ion batteries comprises first and second lithium ion secondary batteries connected in parallel, the first lithium ion secondary battery including an anode active material layer with a thickness in the range of 10 to 40 ?m and a cathode active material layer with a thickness in the range of 10 to 40 ?m, the second lithium ion secondary battery having a volumetric energy density of 250 Wh/l or more. Therefore, the combination of lithium ion batteries can be charged with less charging time than conventional batteries, and can also ensure a high cycle characteristic and safety.
    Type: Application
    Filed: February 6, 2006
    Publication date: September 7, 2006
    Applicant: TDK CORPORATION
    Inventors: Tsuyoshi Iijima, Kazuya Ogawa
  • Publication number: 20060008705
    Abstract: A lithium ion secondary battery having a positive electrode 3 which contains, as a positive electrode active material, a composite metal oxide containing at least one of Li, Co, Mn, and Ni as a metal component thereof; a negative electrode 2 which contains a negative electrode active material; and a nonaqueous electrolyte solution containing a lithium salt. A charging method is characterized in that constant-current charging is performed with use of a set charging current value of equal to or greater than 0.5C and less than 2C (ā€œCā€ referred to here is a rated capacity value of said lithium ion second battery).
    Type: Application
    Filed: July 6, 2005
    Publication date: January 12, 2006
    Applicant: TDK Corporation
    Inventors: Tsuyoshi Iijima, Kazuya Ogawa