Patents by Inventor Marca M. Doeff

Marca M. Doeff 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: 20110291043
    Abstract: A mixed transition metal oxide is provided described wherein Aluminum is partially substituted for Cobalt in a Li[NixCoyMnz]O2 composition wherein the resulting aluminum substituted product Li[Ni0.4Co0.2-yAlyMn0.4]O2 is less costly than the parent product, is safer to use, and provides enhanced electrochemical performance as a cathode material for use in Lithium-ion based batteries.
    Type: Application
    Filed: September 23, 2009
    Publication date: December 1, 2011
    Applicant: The Regents of the University of California
    Inventors: James D. Wilcox, Marca M. Doeff
  • Publication number: 20090183650
    Abstract: Several synthetic additives have been used to improve the carbon coatings on LiFePO4 electrode materials. Pyromellitic acid (PA) added prior to calcination decreases the D/G ratios of the carbon produced in situ, while the use of both iron nitrate and PA results in increased sp2 character. Thus, the carbon coatings are structured with a greater fraction of graphitic character. The production of structured carbon coatings results in higher pressed pellet conductivities of LiFePO4/C composites and improved electrochemical performance of cells containing these cathode materials, although the carbon content is not necessarily increased. The combination of both ferrocene and PA used during LiFePO4 synthesis causes more carbon to be retained, although the structural characteristics are similar to that produced from the same amount of PA alone.
    Type: Application
    Filed: June 12, 2007
    Publication date: July 23, 2009
    Applicant: The Regents of the University of California
    Inventors: Marca M. Doeff, James D. Wilcox, Robert Kostecki, Grace Y. Lau
  • Patent number: 5916710
    Abstract: A solid state secondary battery utilizing a low cost, environmentally sound, sodium cobalt bronze electrode. A method is provided for producing same.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: June 29, 1999
    Assignee: The Regents of The University of California
    Inventors: Marca M. Doeff, Yanping Ma, Steven J. Visco, Lutgard DeJonghe
  • Patent number: 5558961
    Abstract: An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M.sub.x Z.sub.y Mn.sub.(1-y) O.sub.2, where M is an alkali metal; Z is a metal capable of substituting for manganese in the orthorhombic structure such as iron, cobalt or titanium; x ranges from about 0.2 in the fully charged state to about 0.75 in the fully discharged state, and y ranges from 0 to 60 atomic %.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: September 24, 1996
    Assignee: Regents, University of California
    Inventors: Marca M. Doeff, Marcus Y. Peng, Yanping Ma, Steven J. Visco, Lutgard C. DeJonghe
  • Patent number: 5443601
    Abstract: A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: August 22, 1995
    Assignee: Regents, University of California
    Inventors: Marca M. Doeff, Yanping Ma, Steven J. Visco, Lutgard DeJonghe
  • Patent number: 5442478
    Abstract: An electrochromic cell is disclosed which comprises an electrochromic layer and a composite ion counter electrode for transporting ions. The counter electrode further comprises a polymer electrolyte material and an organosulfur material in which, in its discharged state, the organosulfur material is further comprised of a mercaptan or an organothiolate. In one preferred embodiment, both the electrochromic electrode and the counter electrode are transparent either to visible light or to the entire electromagnetic spectrum in both charged and discharged states. An electrochromic device is disclosed which comprises one or more electrochromic electrodes encased in glass or plastic plates on the inner surface of each of which is formed a transparent electrically conductive film. Electrical contacts, which are in electrical contact with the conductive films, facilitate external electrical connection.
    Type: Grant
    Filed: April 23, 1992
    Date of Patent: August 15, 1995
    Assignee: The Regents, University of California
    Inventors: Carl M. Lampert, Yan-ping Ma, Marca M. Doeff, Steven Visco