Patents by Inventor Kenshin Kitoh

Kenshin Kitoh 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).

  • Publication number: 20050100785
    Abstract: A lithium secondary cell includes an internal electrode body having a positive electrode plate and a negative electrode plate wound and laminated around an external peripheral wall of a hollow cylindrical winding core. The inside of the internal electrode body is impregnated with a nonaqueous electrolyte solution. A cylindrical cell case houses the internal electrode body and has open ends sealed with plate member electrode caps. An external terminal member protrudes onto the surface of the electrode caps to lead current to the outside of the cell case, and an internal terminal member connects with the internal electrode body to take current from the internal electrode body. An elastic body and at least two of the plate member, the external terminal member and the internal terminal member are joined together for construction. An assembly of lithium secondary cells is also disclosed.
    Type: Application
    Filed: December 13, 2004
    Publication date: May 12, 2005
    Applicant: NGK Insulators, Ltd.
    Inventors: Akio Enomoto, Kenji Kawamura, Kenshin Kitoh, Toshihiro Yoshida, Hiroshi Nemoto, Shinji Otsubo
  • Patent number: 6884541
    Abstract: A lithium secondary battery includes a cylindrical battery case provided with electrode caps at both end portions thereof. An electrode body impregnated with a nonaqueous electrolyte solution is contained in the battery case and includes a positive electrode, a negative electrode, and a separator, with the positive electrode and the negative electrode being wound or laminated through the separator. An elastic body is disposed between the battery case and the electrode caps, with portions in which the battery case contacts the elastic body being brought into press-contact to form a caulked portion to seal the battery case. Rbody(mm) is a diameter of a body part of the battery case and Rtop(mm) is a diameter of the caulked portion, wherein Rbody and Rtop fulfill a relationship of Rbody>Rtop.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: April 26, 2005
    Assignee: NGK Insulators, Ltd.
    Inventors: Akio Enomoto, Kenji Kawamura, Kenshin Kitoh, Toshihiro Yoshida
  • Publication number: 20050079405
    Abstract: A lithium secondary battery comprises an internal electrode body formed by winding a positive electrode and a negative electrode on an outer peripheral wall of a hollow winding core, nonaqueous electrolyte solution contained in the case, a cylindrical battery case containing this internal electrode body inside, at least one electrode cap sealing the internal electrode body, and at least one pressure release hole in a position corresponding with the center axis of the winding core.
    Type: Application
    Filed: July 13, 2004
    Publication date: April 14, 2005
    Applicant: NGK Insulators, Ltd
    Inventors: Akio Enomoto, Kenji Kawamura, Kenshin Kitoh, Toshihiro Yoshida
  • Patent number: 6875540
    Abstract: A lithium secondary battery comprising a case, an internal electrode body inside the case, electrolyte contained in the case, and an insulator between the case and a terminal. Also, a lithium secondary battery comprising a body member, electrolyte contained in the body member, an internal electrode body inside the body member, an and cap and an insulator between the body member and the end cap. In each battery, the internal electrode body comprises a positive electrode, a negative electrode and a separator between the electrodes, being electrically insulated from each other. In each battery, a first terminal is electrically connected to the negative electrode, and a second terminal is electrically connected to the positive electrode. The insulator comprises ethylene-propylene rubber, has surface hardness of from 30 (durometer A) to 60 (durometer D), and has volume resistivity of at least 1010 ?-cm.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: April 5, 2005
    Assignee: NGK Insulators, Ltd.
    Inventors: Hiroshi Nemoto, Teruhisa Kurokawa, Kenshin Kitoh
  • Patent number: 6866961
    Abstract: A lithium secondary battery has an internal electrode body formed by winding a positive electrode and a negative electrode on an outer peripheral wall of a hollow winding core and filled with nonaqueous electrolyte solution, a cylindrical battery case containing this internal electrode body 1 inside with its both ends being open, and electrode caps which each have a battery cap, an internal terminal, and an external terminal, the internal electrode body being sealed by the electrode caps at both open ends of the battery case. At least one of the electrode caps has a pressure release hole in a position corresponding with the center axis of the winding core.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: March 15, 2005
    Assignee: NGK Insulators, Ltd.
    Inventors: Akio Enomoto, Kenji Kawamura, Kenshin Kitoh, Toshihiro Yoshida
  • Patent number: 6858342
    Abstract: Provided are a method for filling an electrolyte solution and a battery structure of a lithium secondary battery comprising an internal electrode body formed by winding a positive electrode, and a negative electrode, with a separator sandwiched therebetween around the outer periphery of a core, and an electrolyte solution to impregnate said internal electrode body; said method being excellent in productivity, and battery performance as well, and being characterized by an easy filling of an electrode solution, with minimization of excessive electrode solution in the battery, by virtue of the provision of an electrolyte solution injection opening in a specific position, through which the electrolyte solution is injected and extracting efficiently by using a nozzle for injection and/or extraction of electrolyte solution.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: February 22, 2005
    Assignee: NGK Insulators, Ltd.
    Inventors: Hiroshi Nemoto, Kenshin Kitoh, Akio Enomoto
  • Patent number: 6858348
    Abstract: A lithium secondary battery is provided in which even if the depth of discharge becomes deep, lowering of an power is small, and charging and discharging characteristics are excellent, and which is suitably used particularly as a battery for driving a motor of an electric vehicle or the like. In the lithium secondary battery, an internal electrode body formed by winding a positive electrode and a negative electrode through a separator made of porous polymer is contained in a battery case, and an organic electrolyte is used. An power at a depth of discharge of 80% is not smaller than 60% of an power at a depth of discharge of 0%.
    Type: Grant
    Filed: July 25, 2002
    Date of Patent: February 22, 2005
    Assignee: NGK Insulators, Ltd.
    Inventor: Kenshin Kitoh
  • Patent number: 6844110
    Abstract: To provide a lithium secondary cell, which is excellent in productivity since a cell structure is simple and easy for assembly. Provided is a lithium secondary cell having: an internal electrode body including a positive electrode plate, a negative electrode plate, the positive electrode plate and the negative electrode plate being wound and laminated around an external periphery wall of a hollow cylindrical winding core, and inside the internal electrode body a nonaqueous electrolyte solution being impregnated, a cylindrical cell case contained in this internal electrode body 1 with both ends being opened, and two electrode caps sealing the above described internal electrode body 1 at both the open ends of this cell case.
    Type: Grant
    Filed: May 22, 2001
    Date of Patent: January 18, 2005
    Assignee: NGK Insulators, Ltd.
    Inventors: Akio Enomoto, Kenji Kawamura, Kenshin Kitoh, Toshihiro Yoshida, Hiroshi Nemoto, Shinji Otsubo
  • Patent number: 6841297
    Abstract: A lithium secondary battery includes: a battery case, and an internal electrode body 1 contained in the battery case and including a positive electrode 2, a negative electrode 3, and a separator 4 made of porous polymer. The positive electrode and the negative electrode are wound and laminated through the separator so that the positive electrode and the negative electrode are not brought into direct contact each other. The battery case is composed of pure aluminum or aluminum alloy in which one or more components selected from manganese, magnesium, silicon and copper is added in aluminum. The lithium secondary battery has high weight energy density, is superior in safety, and is used for, particularly, an electric vehicle.
    Type: Grant
    Filed: October 15, 2001
    Date of Patent: January 11, 2005
    Assignee: NGK Insulators, Ltd.
    Inventors: Kenshin Kitoh, Hiroshi Nemoto
  • Patent number: 6800394
    Abstract: A lithium secondary battery includes a battery case, an internal electrode body contained in the battery case and including a positive electrode, a negative electrode and a separator made of porous polymer, the positive electrode and the negative electrode are wound or laminated. A working volume ratio of the positive active material and the negative active material obtained by the positive active material weight being divided by the negative active material weight is within the range from 40% to 90% of the theoretical working volume ratio. the lithium secondary battery has high safety as well as high energy density by controlling the working volume of an electrode active material and the dispersion of the distribution of the working volume and in particular is preferably used for a drive motor of an electric vehicle.
    Type: Grant
    Filed: November 4, 2002
    Date of Patent: October 5, 2004
    Assignee: NGK Insulators, Ltd.
    Inventors: Kenshin Kitoh, Hiroshi Nemoto
  • Publication number: 20040191627
    Abstract: A lithium secondary battery superior in the suppression of increasing internal resistance ratio and discharge capacity maintenance ratio and being simple in structure and inexpensive. A lithium secondary battery comprises a positive active material comprising a lithium aluminum manganese oxide having a spinel structure and an aluminum compound other than the lithium aluminum manganese oxide. A ratio of an amount of aluminum contained in the aluminum compound to a total amount of aluminum contained in the positive active material is within a range of 1% by weight or more to 50% by weight or less. The lithium aluminum manganese oxide is represented by a general formula Li1+xAlyMn2−x−yO4, wherein x and y denote constituting ratios of elements in one molecule, x≧0, y≧0.01, and has a lattice constant of 8.245 Å or less. A part of Mn may be replaced with an element other than Li and Al.
    Type: Application
    Filed: February 26, 2004
    Publication date: September 30, 2004
    Applicant: NGK Insulators, Ltd.
    Inventors: Michio Takahashi, Kenshin Kitoh
  • Patent number: 6767666
    Abstract: A lithium secondary cell includes an inner electrode body impregnated with a non-aqueous electrolyte. The inner electrode body includes a positive electrode and a negative electrode wound or laminated together with a separator inserted therebetween. A cell case contains the inner electrode body and includes an electrode cover sealing the inner electrode body and is provided with cell covers, external terminals and internal terminals. The lithium secondary cell is provided with a unit for cooling the electric current path. The lithium secondary cell is capable of preventing a lowering of performance and extending the service life by preventing heating of the lithium secondary cell and maintaining the cell temperature within an adequate range.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: July 27, 2004
    Assignee: NGK Insulators, Ltd.
    Inventors: Hiroshi Nemoto, Kenshin Kitoh
  • Patent number: 6753104
    Abstract: A lithium secondary battery includes an internal electrode body including a positive electrode, a negative electrode, and a separator. The positive electrode and the negative electrode are wound or laminated via the separator so that the positive electrode and the negative electrode are not brought into direct contact with each other. At least a plurality of tabs for current collecting were provided to have a total cross-sectional area of the tabs be not less than a constant area in accordance with the quality of the material to be used for the tabs so that the tabs to be connected to each of the positive and negative electrodes may not respectively fuse when at least 100 A current has flown through the lithium secondary battery. The lithium secondary battery maintains a good charge-discharge cycle characteristics, and safety may be secured with electricity being cut off when an excess current has occurred due to external short circuit, etc., so that the battery may not be exploded nor be ignited.
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: June 22, 2004
    Assignee: NGK Insulators, Ltd.
    Inventor: Kenshin Kitoh
  • Patent number: 6616715
    Abstract: A lithium secondary battery includes a battery case, an internal electrode body contained in the battery case and including a positive electrode, a negative electrode and a separator made of porous polymer, the positive electrode and the negative electrode are wound or laminated. A working volume ratio of the positive active material and the negative active material obtained by the positive active material weight being divided by the negative active material weight is within the range from 40% to 90% of the theoretical working volume ratio. The lithium secondary battery has high safety as well as high energy density by controlling the working volume of an electrode active material and the dispersion of the distribution of the working volume and in particular is preferably used for a drive motor of an electric vehicle.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: September 9, 2003
    Assignee: NGK Insulators, Ltd.
    Inventors: Kenshin Kitoh, Hiroshi Nemoto
  • Patent number: 6569557
    Abstract: A lithium secondary battery includes: an internal electrode body including a positive electrode, a negative electrode, and a separator, the positive electrode and the negative electrode being wound or laminated via the separator, and an organic electrolyte. The active material used in the positive electrode satisfies the following relation between the average particle diameter R (&mgr;m) and the specific surface area S (m2/g): 6≦R×S≦50 The amount of the acetylene black added to the positive electrode active material satisfies the following relation with the specific surface area of the positive electrode active material: S≦W≦S+5 (W≦10) (W is the amount of the acetylene black added to the positive electrode active material, expressed in % by weight based on the amount of the active material, and S is expressed in m2/g.) In this battery, the electron conductivity is improved, and the internal resistance is reduced.
    Type: Grant
    Filed: September 9, 1999
    Date of Patent: May 27, 2003
    Assignee: NGK Insulators, Ltd.
    Inventors: Kenshin Kitoh, Teruhisa Kurokawa
  • Publication number: 20030087158
    Abstract: To provide a lithium secondary battery with a high critical discharge current even under a low temperature condition, with an excellent cycle characteristic and reduced manufacturing cost. This lithium secondary battery includes a wound type electrode body comprising a positive electrode plate, and a negative electrode plate both of which have been wound around a core via a separator; said electrode body being impregnated with a non-aqueous electrolyte, and a cylindrical case for housing the electrode body and the non-aqueous electrolyte; the case having at least one opening at either end thereof; said at least one opening being sealed. The separator is subjected to drying treatment before assembly.
    Type: Application
    Filed: November 4, 2002
    Publication date: May 8, 2003
    Applicant: NGK Insulators, Ltd.
    Inventors: Toshihiko Nakagawa, Kenshin Kitoh, Hiroshi Nemoto, Toshihiro Yoshida
  • Publication number: 20030064285
    Abstract: A lithium secondary battery 10 is provided with an inner electrode body 1 comprising a positive electrode plate and a negative electrode plate respectively made up of at least one metal foil 6 wound or laminated; said inner electrode body being impregnated with a non-aqueous electrolyte, current collector members 5A and 5B for leading a current out of this inner electrode body 1, a battery case 11 with both ends left open; said battery case housing the inner electrode body 1, and two caps 13 provided with internal terminals 14A and 14B thereon; said caps being used to seal the inner electrode body 1 at both open ends of the battery 11. By adopting such a configuration that positive and negative external terminals are placed on one end of a battery collectively, protrusions of the battery are so reduced that the collective coupling of batteries becomes easier.
    Type: Application
    Filed: September 30, 2002
    Publication date: April 3, 2003
    Applicant: NGK Insulators, Ltd.
    Inventors: Kenji Kawamura, Kenshin Kitoh
  • Publication number: 20030054231
    Abstract: A lithium secondary battery includes a battery case, an internal electrode body contained in the battery case and including a positive electrode, a negative electrode and a separator made of porous polymer, the positive electrode and the negative electrode are wound or laminated. A working volume ratio of the positive active material and the negative active material obtained by the positive active material weight being divided by the negative active material weight is within the range from 40% to 90% of the theoretical working volume ratio. the lithium secondary battery has high safety as well as high energy density by controlling the working volume of an electrode active material and the dispersion of the distribution of the working volume and in particular is preferably used for a drive motor of an electric vehicle.
    Type: Application
    Filed: November 4, 2002
    Publication date: March 20, 2003
    Applicant: NGK Insulators, Ltd.
    Inventors: Kenshin Kitoh, Hiroshi Nemoto
  • Publication number: 20030035993
    Abstract: A lithium secondary battery, includes: a cylindrical battery case (16) provided with electrode caps at both end portions thereof; an electrode body (1) impregnated with a nonaqueous electrolyte solution and contained in the battery case and including a positive electrode, a negative electrode, and a separator, the positive electrode and the negative electrode being wound or laminated through the separator; and moreover, an elastic body (23) disposed between the battery case (16) and the electrode caps with portions in which the battery case (16) contacts the elastic body (23) being brought into press-contact to form a caulked portion to seal the battery case (16). With Rbody (mm) being diameter of a body part of the battery case (16), Rtop (mm) being diameter of the caulked portion, Rbody and Rtop fulfill relationship of Rbody>Rtop.
    Type: Application
    Filed: October 2, 2001
    Publication date: February 20, 2003
    Inventors: Akio Enomoto, Kenji Kawamura, Kenshin Kitoh, Toshihiro Yoshida
  • Patent number: 6506515
    Abstract: A lithium secondary battery including an internal electrode body contained in a battery case including a positive electrode, a negative electrode and a separator made of porous polymer, the positive electrode and the negative electrode are wound or laminated. A working volume ratio of the positive active material and the negative active material obtained by the positive active material weight being divided by the negative active material weight is within the range from 40% to 90% of the theoretical working volume ratio. The lithium secondary battery has high safety as well as high energy density by controlling the working volume of an electrode active material and the dispersion of the distribution of the working volume and in particular is preferably used for a drive motor of an electric vehicle.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: January 14, 2003
    Assignee: NGK Insulators, Ltd.
    Inventors: Kenshin Kitoh, Hiroshi Nemoto