Patents by Inventor Gayatri Vyas

Gayatri Vyas 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: 7344798
    Abstract: A separator assembly for use in a stack of electrochemical cells is provided, having a first conductive metallic substrate with a first surface and a second conductive metallic substrate with a second surface, wherein each of the first and second surfaces are overlaid with an ultra-thin electrically conductive metal coating. The first and second surfaces form electrically conductive paths at regions where the metal coating of the first and second layer contact one another. The contact of the surfaces overlaid with metal coating is sufficient to join the first and second substrates to one another. Preferred metal coatings comprise gold (Au). Methods of making such separator assemblies are also provided.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: March 18, 2008
    Assignee: General Motors Corporation
    Inventors: Gayatri Vyas, Michael Budinski, Brian K Brady, Michael J Lukitsch, Harald Schlag
  • Publication number: 20080050643
    Abstract: A product including a fuel cell gas diffusion media layer and a plurality of electrically conductive lands secured thereto.
    Type: Application
    Filed: August 24, 2006
    Publication date: February 28, 2008
    Applicant: GM Global Technology Operations, Inc.
    Inventors: Mahmoud H. Abd Elhamid, Gayatri Vyas, Youssef M. Mikhail, Thomas A. Trabold
  • Publication number: 20080044716
    Abstract: A bipolar plate for a fuel cell that includes a hydrophilic layer deposited on the bipolar plate to a suitable thickness to satisfy hydrofluoric acid etching for the desired lifetime of the fuel cell. In one embodiment, the hydrophilic layer is a relatively thick silicon dioxide layer that is deposited on the bipolar plate as a colloidal dispersion of silicon dioxide nano-particles in a solvent. The dispersion is dried so that the solvent evaporates to form a film of the silicon dioxide nano-particles on the bipolar plate. A relatively thin layer, generally a metal oxide, is first deposited on the bipolar plate by a CVD or PVD process so that the thin layer has suitable bonding to the bipolar plate. The thicker hydrophilic layer is then deposited on the thin layer, where the bonds between the thick layer and the thin layer are suitable for the fuel cell environment.
    Type: Application
    Filed: August 16, 2006
    Publication date: February 21, 2008
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Mahmoud H. Abd Elhamid, Gayatri Vyas, Youssef M. Mikhail
  • Publication number: 20080044715
    Abstract: A fluid distribution element is provided for a fuel cell having a major surface facing a membrane electrode assembly (MEA) and one or more flow channels for transporting gas and liquid to and from the MEA. One or more regions of the major surface are overlaid with a super-hydrophilic corrosion-resistant layer comprising a fluoropolymer. Methods of making such a fluid distribution element are also provided.
    Type: Application
    Filed: September 15, 2005
    Publication date: February 21, 2008
    Inventors: Gayatri Vyas, Youssef M. Mikhail, Thomas A. Trabold
  • Publication number: 20070298309
    Abstract: A method for depositing a hydrophilic and electrically conductive layer onto a bipolar plate substrate for a fuel cell in a one step process. The method includes mixing a solution of a conductive material, such as gold particles, and a hydrophilic material, such as silicon dioxide particles, in a suitable solvent, such as ethanol. The solution is then deposited on the bipolar plate substrate by any suitable low cost process. Once the solution dries and the ethanol has evaporated, a thin layer of the conductive and hydrophilic particles remains on the substrate. In one embodiment, the conductive particles are significantly larger than the hydrophilic particles to provide both the desirable hydrophilicity and the low contact resistance.
    Type: Application
    Filed: June 27, 2006
    Publication date: December 27, 2007
    Inventors: Gayatri Vyas, Upendra Rao
  • Publication number: 20070238006
    Abstract: A flow field plate or bipolar plate for a fuel cell that includes a carbon nano tube or carbon nano fiber coating that makes the bipolar plate conductive hydrophilic. Further, the carbon nano tube or carbon nano fiber coating is stable in the fuel cell environment and does not corrode.
    Type: Application
    Filed: August 30, 2005
    Publication date: October 11, 2007
    Inventors: Gayatri Vyas, Mahmoud Elhamid, Youssef Mikhail
  • Publication number: 20070207364
    Abstract: Devices comprising an electrochemical conversion assembly comprise a plurality of electrochemical conversion cells, and a plurality of electrically conductive bipolar plates, wherein the electrochemical conversion cells are disposed between the adjacent bipolar plates. The electrochemical conversion assembly further comprises a plurality of conversion assembly gaskets, wherein the respective conversion assembly gaskets are molded onto corresponding ones of the plurality of bipolar plates. The conversion assembly gaskets comprise a mixture including polyvinylidene fluoride (PVDF).
    Type: Application
    Filed: March 3, 2006
    Publication date: September 6, 2007
    Inventors: Mahmoud Abd Elhamid, Youssef Mikhail, Daniel Lisi, Gayatri Vyas
  • Publication number: 20070178357
    Abstract: A flow field plate or bipolar plate for a fuel cell that includes a conductive coating having formed nanopores that make the coating hydrophilic. Any suitable process can be used to form the nanopores in the coating. One process includes co-depositing a conductive material and a relatively unstable element on the plate, and then subsequently dissolving the element to remove it from the coating and create the nanopores. Another process includes using low energy ion beams for ion beam lithography to make the nanopores.
    Type: Application
    Filed: January 27, 2006
    Publication date: August 2, 2007
    Inventors: Gayatri Vyas, Mahmoud Abd Elhamid, Youssef Mikhail, Thomas Trabold
  • Publication number: 20070178356
    Abstract: A bi-polar plate is provided for a fuel cell stack. The bi-polar plate has improved surface wettability. The bi-polar plate includes a body including at least approximately ninety percent by weight of a metal and defining at least one flow channel. At least about 0.05 percent and up to 100 percent by weight of silicon is disposed on a surface of the at least one flow channel to form a high energy surface to form a high energy surface for the bi-polar plate. This can be achieved by adding from 0.5 to 10 weight % silicon to the steel. The percent of silicon is pre-determined based on a desired wettability of the high energy surface of the at least one flow channel.
    Type: Application
    Filed: January 27, 2006
    Publication date: August 2, 2007
    Inventors: Keith Newman, Mahmoud Abd Elhamid, Charles Olk, Thomas Trabold, Gayatri Vyas
  • Publication number: 20070141439
    Abstract: A flow field plate or bipolar plate for a fuel cell, where a surface of the flow field plate is textured or roughened to change the surface morphology of the plate. A conductive coating is deposited on the roughened surface where the roughness of the surface of the plate increases the hydrophilic nature of the coating. Therefore, if the coating is naturally hydrophobic, the surface roughness makes the coating hydrophilic to wick water away. If the coating is a conductive hydrophilic coating, then the surface roughness makes the coating super-hydrophilic, and may counter the effects of surface contamination that would act to make the hydrophilic coating less hydrophilic.
    Type: Application
    Filed: December 20, 2005
    Publication date: June 21, 2007
    Inventors: Gayatri Vyas, Mahmoud Elhamid, Youssef Mikhail, Thomas Trabold
  • Publication number: 20070116993
    Abstract: A fuel cell system that employs a surface active agent that reduces the surface tension of the water in the flow field channels. The fuel cell system includes humidifiers that humidify the cathode inlet airflow and the hydrogen anode gas. The surface active agent is mixed with the humidifying water in the humidifiers so that the surface active agent enters the flow field channels to reduce the surface tension of the water therein, thus allowing the water to wick the channels. In one non-limiting embodiment, the surface active agent is ethanol. Ruthenium can be added to the platinum in the catalyst layers of the fuel cells to mitigate the poisoning of platinum by carbon monoxide, which is one of the oxidation products of ethanol on the cathode side of the fuel cell.
    Type: Application
    Filed: November 23, 2005
    Publication date: May 24, 2007
    Inventors: Mahmoud Abd Elhamid, Gayatri Vyas, Youssef Mikhail
  • Publication number: 20070117003
    Abstract: A flow field plate or bipolar plate for a fuel cell that includes a carbide coating that makes the bipolar plate conductive, hydrophilic and stable in the fuel cell environment. Suitable carbides include, but are not limited to, chromium carbide, titanium carbide, tantalum carbide, niobium carbide and zirconium carbide. The carbide coating is then polished or textured by a suitable process, such as laser or chemical etching, to provide a surface morphology that makes the coating more hydrophilic, and further reduces the contact resistance on its surface.
    Type: Application
    Filed: November 23, 2005
    Publication date: May 24, 2007
    Inventors: Mahmoud Abd Elhamid, Gayatri Vyas, Youssef Mikhail, Thomas Trabold
  • Publication number: 20070092780
    Abstract: A fuel cell component having a coating thereon including binary and ternary nitrides and oxynitrides of elements of IVb and Vb groups of the periodic table of elements.
    Type: Application
    Filed: September 28, 2006
    Publication date: April 26, 2007
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Gayatri Vyas, Thomas Trabold, Mahmoud Abd Elhamid, Youssef Mikhail, Roy Gordon, Dawen Pang
  • Publication number: 20070048588
    Abstract: In at least one embodiment, the present invention provides an electrically conductive fluid distribution separator plate assembly, a method of making, and a system for using, the electrically conductive fluid distribution separator plate assembly. In at least one embodiment, the electrically conductive fluid distribution separator plate assembly comprises a metallic cathode plate having opposed surfaces and a first contact resistance, a polymeric composite anode plate adjacent to the metallic cathode plate, and a low contact resistance coating located on at least one of the surfaces of the plates, with the coating having a second contact resistance, less-than the first contact resistance.
    Type: Application
    Filed: August 30, 2005
    Publication date: March 1, 2007
    Inventors: Mahmoud Abd Elhamid, Youssef Mikhail, Richard Blunk, John Owens, Daniel Lisi, Gayatri Vyas
  • Publication number: 20070037036
    Abstract: One embodiment disclosed includes a product comprising: a fuel cell component comprising a substrate and a first coating overlying the substrate, the coating comprising a compound comprising at least one Si—O group, at least one polar group and at least one group including a saturated or unsaturated carbon chain.
    Type: Application
    Filed: August 9, 2006
    Publication date: February 15, 2007
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Gerhard Winter, Gayatri Vyas, Thomas Trabold, Reena Datta
  • Publication number: 20070036891
    Abstract: A method of making a fuel cell component using a mask, which is removed after further processing to yield a surface with variable properties.
    Type: Application
    Filed: August 9, 2006
    Publication date: February 15, 2007
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Scott Peters, Thomas Trabold, Gayatri Vyas, Reena Datta, Jeffrey Guzda
  • Publication number: 20070031721
    Abstract: A process comprising: depositing a coating on a fuel cell bipolar plate using plasma assisted chemical vapor deposition.
    Type: Application
    Filed: August 9, 2006
    Publication date: February 8, 2007
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Gerhard Winter, Gayatri Vyas, Thomas Trabold, Reena Datta
  • Publication number: 20070031723
    Abstract: A fuel cell that employs a decomposition catalyst on one or more of the membrane, bipolar plates or diffusion media layers in the fuel cell that decomposes hydrogen peroxide, and thus reduces the generation of hydroxyl free radicals. In one embodiment, the decomposition catalyst is ruthenium oxide and is deposited on the structure by various processes, such as chemical vapor deposition process.
    Type: Application
    Filed: August 3, 2005
    Publication date: February 8, 2007
    Inventors: Youssef Mikhail, Mahmoud Abd Elhamid, Gayatri Vyas
  • Publication number: 20070015029
    Abstract: In accordance with one embodiment of the present invention, an electrochemical conversion assembly comprises a plurality of electrochemical conversion cells and a plurality of electrically conductive bipolar plates. The electrochemical conversion cells are configured to communicate with first and second reactant supplies. Adjacent ones of the electrochemical conversion cells are separated by respective ones of the plurality of bipolar plates. The bipolar plates comprise an alloy comprising Fe and Cr. Respective surface portions of the bipolar plates are provided with electrically conductive, corrosion resistant layers that are placed in contact with portions of the electrochemical conversion cells. The corrosion resistant electrically conductive layers may comprise graphitic layers characterized predominantly by sp2 hybridized carbon-carbon bonding, molybdenum doped indium oxide layers, an electrically conductive Cr+N layer, or an electrically conductive MoSi2 layer.
    Type: Application
    Filed: July 12, 2005
    Publication date: January 18, 2007
    Inventors: Michael Budinski, Gayatri Vyas, Augusto Kunrath Neto, John Moore
  • Publication number: 20070015034
    Abstract: An electrically conductive separator element and assembly for a fuel cell which comprises an electrically conductive substrate having a monoatomic layer coating overlying the substrate. The monatomic layer coating may comprise an electrically conductive material, for example, a noble metal, desirably Ru, Rh, Pd, Ag, Ir, Os and preferably Au. Methods of making such separator elements and assemblies are also provided.
    Type: Application
    Filed: September 20, 2006
    Publication date: January 18, 2007
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Gayatri Vyas, Mahmoud Elhamid, Youssef Mikhail