Patents by Inventor Yoshitada Tomioka

Yoshitada Tomioka 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).

  • Positive electrode active material for a secondary battery, secondary battery and process of manufacturing positive electrode active material for a secondary battery
    Patent number: 7335444
    Abstract: A positive electrode active material containing lithium manganate having a spinel structure is used, wherein the value of a* of the L*a*b* color specification system is made to satisfy the requirement: ?3.2 ?a*??1.4. Or, the value of a* is made to satisfy the requirement: ?5.8 23 a*??4.2. Or, the value of L* is made to satisfy the requirement: 24 ?L*?27.
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: February 26, 2008
    Assignee: NEC Corporation
    Inventors: Tatsuji Numata, Yoshitada Tomioka
  • Positive electrode active material for a secondary battery, secondary battery and process of manufacturing positive electrode active material for a secondary battery
    Publication number: 20060019166
    Abstract: A positive electrode active material containing lithium manganate having a spinel structure is used, wherein the value of a* of the L*a*b* color specification system is made to satisfy the requirement: ?3.2?a*??1.4. Or, the value of a* is made to satisfy the requirement: ?5.8?a*??4.2. Or, the value of L* is made to satisfy the requirement: 24?L*?27.
    Type: Application
    Filed: September 28, 2005
    Publication date: January 26, 2006
    Inventors: Tatsuji Numata, Yoshitada Tomioka
  • Lithium manganese compound oxide and non-aqueous electrolyte secondary battery
    Publication number: 20030091900
    Abstract: The present invention provides a lithium manganese oxide, wherein a content of sulfur is not more than 0.32% by weight, and an averaged diameter of pores is not less than 120 nanometers, and the lithium manganese oxide is represented by Li1+xMn2−x−yMyO4, where “M” is at least one of metals and 0.032≦x≦0.182; 0≦y≦0.2, and also provides a non-aqueous electrolyte secondary battery using the above lithium manganese compound oxide as a positive electrode active material.
    Type: Application
    Filed: November 30, 2000
    Publication date: May 15, 2003
    Inventors: Tatsuji Numata, Chika Kanbe, Yoshitada Tomioka, Masato Shirakata