Patents by Inventor Naoki Kumada

Naoki Kumada 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: 11848441
    Abstract: A zinc foil is provided that can be used as a negative electrode active material, and in a battery including the zinc foil as a negative electrode active material, the amount of gas generated during long term storage of the battery is reduced as compared with that in a battery including a conventional zinc foil. The zinc foil contains zinc as a main material and bismuth. The bismuth content is 100 ppm or more and 10000 ppm or less on a mass basis. The zinc crystal grain size is 0.2 ?m or more and 8 ?m or less. The bismuth crystal grain size is less than 1000 nm, as measured in a backscattered electron image obtained using a scanning electron microscope. The zinc foil is free of aluminum and/or lead, or even if the zinc foil contains aluminum and/or lead, the aluminum content is 1% or less on a mass basis and/or the lead content is 200 ppm or less on a mass basis.
    Type: Grant
    Filed: October 1, 2019
    Date of Patent: December 19, 2023
    Inventors: Tsuneyoshi Kamada, Naoki Kumada, Masashi Sakano, Hidetoshi Inoue, Hideyuki Nagaoka, Yasuhiro Ochi
  • Publication number: 20220037654
    Abstract: A zinc foil is provided that can be used as a negative electrode active material, and in a battery including the zinc foil as a negative electrode active material, the amount of gas generated during long term storage of the battery is reduced as compared with that in a battery including a conventional zinc foil. The zinc foil contains zinc as a main material and bismuth. The bismuth content is 100 ppm or more and 10000 ppm or less on a mass basis. The zinc crystal grain size is 0.2 ?m or more and 8 ?m or less. The bismuth crystal grain size is less than 1000 nm, as measured in a backscattered electron image obtained using a scanning electron microscope. The zinc foil is free of aluminum and/or lead, or even if the zinc foil contains aluminum and/or lead, the aluminum content is 1% or less on a mass basis and/or the lead content is 200 ppm or less on a mass basis.
    Type: Application
    Filed: October 1, 2019
    Publication date: February 3, 2022
    Inventors: Tsuneyoshi KAMADA, Naoki KUMADA, Masashi SAKANO, Hidetoshi INOUE, Hideyuki NAGAOKA, Yasuhiro OCHI
  • Patent number: 7988880
    Abstract: In order to provide a novel spinel type lithium transition metal oxide (LMO) having excellent power performance characteristics, in which preferably both the power performance characteristics and the cycle performance at high temperature life characteristics may be balanced, a novel spinel type lithium transition metal oxide with excellent power performance characteristics is proposed by defining the inter-atomic distance Li—O to be 1.978 ? to 2.006 ? as measured by the Rietveld method using the fundamental method in a lithium transition metal oxide represented by the general formula Li1+xM2?xO4 (where M is a transition metal consisting of three elements Mn, Al and Mg and x is 0.01 to 0.08).
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: August 2, 2011
    Assignee: Mitsui Mining & Smelting Co., Ltd.
    Inventors: Naoki Kumada, Shinya Kagei, Yoshimi Hata, Kenji Sasaki, Yasuhiro Ochi, Keisuke Miyanohara
  • Patent number: 7927741
    Abstract: In a lithium transition metal oxide having a layered structure, one is provided, which is particularly excellent as a positive electrode active material of a battery on board of an electric vehicle or a hybrid vehicle in particular. A lithium transition metal oxide having a layered structure is proposed, wherein the ratio of the crystallite diameter determined by Measurement Method 1 according to the Rietveld method with respect to the mean powder particle diameter (D50) determined by the laser diffraction/scattering-type particle size distribution measurement method is 0.05 to 0.20.
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: April 19, 2011
    Assignee: Mitsui Mining & Smelting Co., Ltd.
    Inventors: Tomoya Takeuchi, Shinya Kagei, Naoki Kumada, Keisuke Miyanohara
  • Publication number: 20100243952
    Abstract: In order to provide a novel spinel type lithium transition metal oxide (LMO) having excellent power performance characteristics, in which preferably both the power performance characteristics and the cycle performance at high temperature life characteristics may be balanced, a novel spinel type lithium transition metal oxide with excellent power performance characteristics is proposed by defining the inter-atomic distance Li—O to be 1.978 ? to 2.006 ? as measured by the Rietveld method using the fundamental method in a lithium transition metal oxide represented by the general formula Li1+xM2?xO4 (where M is a transition metal consisting of three elements Mn, Al and Mg and x is 0.01 to 0.08).
    Type: Application
    Filed: October 23, 2008
    Publication date: September 30, 2010
    Applicant: MITSUI MINING & SMELTING CO., LTD.
    Inventors: Naoki Kumada, Shinya Kagei, Yoshimi Hata, Kenji Sasaki, Yasuhiro Ochi, Keisuke Miyanohara
  • Publication number: 20100117025
    Abstract: In a lithium transition metal oxide having a layered structure, one is provided, which is particularly excellent as a positive electrode active material of a battery on board of an electric vehicle or a hybrid vehicle in particular. A lithium transition metal oxide having a layered structure is proposed, wherein the ratio of the crystallite diameter determined by Measurement Method 1 according to the Rietveld method with respect to the mean powder particle diameter (D50) determined by the laser diffraction/scattering-type particle size distribution measurement method is 0.05 to 0.20.
    Type: Application
    Filed: January 28, 2008
    Publication date: May 13, 2010
    Applicant: MITSUI MINING & SMELTING CO., LTD.
    Inventors: Tomoya Takeuchi, Shinya Kagei, Naoki Kumada, Keisuke Miyanohara
  • Publication number: 20060019165
    Abstract: A positive electrode active material for a battery, consisting essentially of manganese dioxide, contains 5 to 400 ppm of magnesium or 0.001 to 3.0% by weight of titanium, thereby achieving even higher performance of a battery, such as enhanced pulse characteristics.
    Type: Application
    Filed: May 22, 2003
    Publication date: January 26, 2006
    Inventors: Munetoshi Yamaguchi, Naoki Kumada, Tsuyoshi Nagaishi, Yasuhiro Ochi, Takeshi Asanuma, Koichi Numata, Shigeo Hirayama
  • Publication number: 20040009400
    Abstract: The present invention provides a battery cathode active material formed of electrolytic manganese dioxide which has a large specific area and a high electric potential and can enhance battery characteristics such as high-rate characteristics and high-rate pulse characteristics when used as a battery cathode active material. The invention also provides a method for producing electrolytic manganese dioxide and a battery employing the cathode active material. The battery cathode active material is formed of electrolytic manganese dioxide containing a sulfate group in an amount of 1.3 to 1.6 wt. %.
    Type: Application
    Filed: May 13, 2003
    Publication date: January 15, 2004
    Applicant: MITSUI MINING & SMELTING CO., LTD.
    Inventors: Munetoshi Yamaguchi, Yasuhiro Ochi, Tsuyoshi Nagaishi, Naoki Kumada, Takeshi Asanuma, Shigeo Hirayama