Patents by Inventor Anil V. Virkar
Anil V. Virkar 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).
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Publication number: 20150017490Abstract: An advanced planar alkali metal-beta battery made by stacking a plurality of individual planar cells, where the individual cells comprises a one-piece ceramic unibody construction with an interior divided by an alkali-ion conducting solid electrolyte into separate cathode and anode compartments. The cathode comprises a premanufactured solid pellet of active cathode materials. A bellows is provided to reduce pressure accumulation in the cathode compartment.Type: ApplicationFiled: July 9, 2013Publication date: January 15, 2015Applicant: Material and Systems Research, Inc.Inventors: Gege Tao, Neill Weber, Anil V. Virkar
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Publication number: 20130337309Abstract: An electrolyte structure that is useful in battery cells having liquid electrodes and solid electrolyte and in alkali-metal thermoelectric converters is made by applying a dense film of a solid alkali-metal ion conductor on a thick porous metal support.Type: ApplicationFiled: May 20, 2013Publication date: December 19, 2013Applicant: Materials and Systems Research, Inc.Inventors: Anil V. VIRKAR, Joon-Ho Koh, Gege Tao, Neill Weber
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Patent number: 8168561Abstract: A core-shell catalyst material can include a core and a shell material. Each of the core material and the shell material can have crystal structures and lattice parameters which allow for a substantially coherent core-shell interface. The shell material can include a catalytically active metal. The circumferential stress of the shell material, ???, at the core-shell interface and at the shell surface, is greater than 0 (tensile) or can be compressive of a lower magnitude than a catalyst made of the shell material alone. The crystal structures of the core material can often be the same as the shell material, although this is not always required.Type: GrantFiled: July 31, 2009Date of Patent: May 1, 2012Assignee: University of Utah Research FoundationInventor: Anil V. Virkar
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Publication number: 20100173213Abstract: The present invention concerns improved configurations for a fuel cell army. The contacts for the positive electrode and the negative electrode are made outside the higher temperature active reaction space in a cooler area. Thus different more common materials are used which have a longer lifetime and have less stresses at their lower operating temperature. The invention utilizes tubular cell components connected with spines for efficient electron transfer and at least two manifolds outside the reaction zone, which may be cooled by external means. The external protruding connectors are thus at a lower operating temperature. This invention improves fuel cell life span, provides for lower cost, use of more common materials, and reduces the number thermal defects during operation.Type: ApplicationFiled: June 30, 2006Publication date: July 8, 2010Applicant: The Regents of the University of CaliforniaInventors: Frederick F. Lange, Anil V. Virkar
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Publication number: 20100062929Abstract: A core-shell catalyst material can include a core and a shell material. Each of the core material and the shell material can have crystal structures and lattice parameters which allow for a substantially coherent core-shell interface. The shell material can include a catalytically active metal. The circumferential stress of the shell material, Gee, at the core-shell interface and at the shell surface, is greater than 0 (tensile) or can be compressive of a lower magnitude than a catalyst made of the shell material alone. The crystal structures of the core material can often be the same as the shell material, although this is not always required.Type: ApplicationFiled: July 31, 2009Publication date: March 11, 2010Inventor: Anil V. Virkar
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Patent number: 6368383Abstract: A method of separating oxygen from an oxygen containing gas with a composite membrane capable of conducting oxygen ions and electrons. In accordance with the method, the composite membrane is subjected to an operational temperature and the oxygen containing gas at a cathode side thereof. The composite membrane has a dense layer, at least one active porous layer contiguous to the dense layer, and at least one porous support layer. The active porous layer has a thickness and a distribution of pore radii. The distribution of pore radii has a standard deviation from a theoretical radius that would produce a maximum operation flux through the thickness when the thickness is about equal to a product of a constant and the square root of the theoretical radius. The constant is a function of a material used to fabricate the active porous layer, the operational temperature and an oxygen partial pressure within the active porous layer, and a porosity and a tortuosity produced by the pore radii.Type: GrantFiled: June 7, 2000Date of Patent: April 9, 2002Assignee: Praxair Technology, Inc.Inventors: Anil V. Virkar, Christian Friedrich Gottzmann, Ravi Prasad, Bart Antonie Van Hassel
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Patent number: 6326096Abstract: A solid oxide fuel cell interconnector having a superalloy metallic layer with an anode-facing face and a cathode-facing face and metal layer on the anode-facing face of the superalloy metallic layer. The metal layer is a metal which does not oxidize in a fuel atmosphere, preferably nickel or copper.Type: GrantFiled: February 4, 1998Date of Patent: December 4, 2001Assignee: Gas Research InstituteInventors: Anil V. Virkar, Diane M. England, Karun Mehta, Jai-Woh Kim, Kuan-Zong Fung
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Patent number: 6228521Abstract: The present invention concerns a high power density solid oxide fuel cell having a cathode, electrolyte and graded porous anode. The graded porosity of the anode allows easy transport of fuel gases thereby minimizing concentration polarization. Power densities of about 1.8 W/cm2 at 800° C. and about 0.8 W/cm2 at about 650° C. have been achieved with graded porous anodes as thick as 0.75 mm. These fuel cells having a graded porous anode are more durable and mechanically reliable than those found in the art.Type: GrantFiled: December 8, 1998Date of Patent: May 8, 2001Assignee: The University of Utah Research FoundationInventors: Jai-Woh Kim, Kuan-Zong Fung, Anil V. Virkar
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Patent number: 6106967Abstract: A solid oxide fuel cell stack having a plurality of integral component fuel cell units, each integral component fuel cell unit having a porous anode layer, a porous cathode layer, and a dense electrolyte layer disposed between the porous anode layer and the porous cathode layer. The porous anode layer forms a plurality of substantially parallel fuel gas channels on its surface facing away from the dense electrolyte layer and extending from one side to the opposite side of the anode layer, and the porous cathode layer forms a plurality of substantially parallel oxidant gas channels on its surface facing away from the dense electrolyte layer and extending from one side to the opposite side of the cathode. A flexible metallic foil interconnect is provided between the porous anode and porous cathode of adjacent integral component fuel cell units.Type: GrantFiled: June 14, 1999Date of Patent: August 22, 2000Assignee: Gas Research InstituteInventors: Anil V. Virkar, Jai-Woh Kim, Kuan-Zong Fung
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Patent number: 6054231Abstract: A solid oxide fuel cell interconnector having a superalloy metallic layer with an anode facing face and a cathode facing face and a metal layer on the anode facing face of the superalloy metallic layer, the metal layer including a metal which reacts with Cr.sub.2 O.sub.3 to form an electronically conducting oxide phase on the superalloy metallic layer. In accordance with one particularly preferred embodiment, a second metal layer is disposed between the metal layer and the superalloy metallic layer, the second metal layer including a metal which does not oxidize in a fuel atmosphere.Type: GrantFiled: July 24, 1998Date of Patent: April 25, 2000Assignee: Gas Research InstituteInventors: Anil V. Virkar, Diane M. England
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Patent number: 5624542Abstract: Enhancement of mechanical properties of ceramic membranes by introduction of a uniformly distributed high-temperature oxidation-resistant metal phase into the brittle ceramic phase to achieve mechanically strong ceramic/metal composites operable in an oxidation atmosphere and at elevated temperatures.Type: GrantFiled: June 12, 1995Date of Patent: April 29, 1997Assignee: Gas Research InstituteInventors: Yousheng Shen, Ashok V. Joshi, Dale M. Taylor, Michael J. Boettcher, Kevin Krist, Anil V. Virkar
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Patent number: 5616223Abstract: Composite ceramic mixed ionic and electronic conducting materials having high ambipolar activity which can be fabricated into thin membranes for high efficiency oxygen separation from air at intermediate temperatures. The mixed conducting materials have composite non-homogeneous microstructures of a separate predominantly oxygen ion conductive phase and a predominantly electronic conductive phase. Preferred predominantly oxygen ion conducting phases include bismuth, cerium and zirconium oxide based materials and predominantly electronic conducting phases include at least one metal electronic conductor material.Type: GrantFiled: April 22, 1994Date of Patent: April 1, 1997Assignee: Gas Research InstituteInventors: Yousheng Shen, Ashok V. Joshi, Kevin Krist, Meilin Liu, Anil V. Virkar
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Patent number: 5580430Abstract: Ceramic materials are disclosed which have comprehensive characteristics of high ion-conductivity for alkali metal cations at low temperatures, high selectivity for alkali metal ions, good current efficiency and stability in water and corrosive media under static and electrochemical conditions. Also disclosed is an electrochemical cell, the electrolyte of which employs the disclosed ceramic materials, for use in electrolysis of aqueous alkali salt solutions to form caustic.Type: GrantFiled: February 28, 1994Date of Patent: December 3, 1996Assignee: Ceramatec, Inc.Inventors: Shekar H. Balagopal, John H. Gordon, Anil V. Virkar, Ashok V. Joshi
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Patent number: 5543239Abstract: An improved electrode design for solid state devices, fuel cells, sensors and the like is made by incorporation of a porous layer of the electrolyte material over the dense electrolyte, and by the introduction of an electrocatalyst into the porous layer such that it is also continuous. The resulting electrode structure of dense electrolyte/porous electrolyte, continuous electrocatalyst and gas phase are present creating an enhanced three phase (TPB) length over that of conventional designs. The design allows for improved performance at lower temperatures which means a lower cost of materials, fewer problems from oxidation and corrosion, and improved durability. In a preferred embodiment, the dense electrolyte and porous electrolyte is yttria-stabilized zirconia (YSZ), and the electrocatalyst is selected from silver; platinum; rhodium; palladium; iridium; ruthenium;(La.sub.1-x Sr.sub.x) MnO.sub.3, wherein x is 0 to 0.5;(La.sub.1-x Sr.sub.x) CoO.sub.3, wherein x is 0 to 0.6;(La.sub.1-x Sr.sub.x)(Co.sub.1-y Fe.Type: GrantFiled: April 19, 1995Date of Patent: August 6, 1996Assignee: Electric Power Research InstituteInventors: Anil V. Virkar, Kuan-Zong Fung, Cameron W. Tanner
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Patent number: 5478444Abstract: A composite ceramic mixed oxygen ion and electronic conducting materials having high ambipolar activity which can be fabricated into thin membranes for high efficiency oxygen separation from air at intermediate temperatures. The mixed conducting materials have composite non-homogeneous microstructures of a separate predominantly oxygen ion conductive phase and a predominantly electronic conductive phase. Predominantly oxygen ion conducting phases include bismuth, cerium and thorium oxide based materials and predominantly electronic conducting phases include at least one metal, metal oxide of at least one metal, and at least one perovskite-type electronic conductor material.Type: GrantFiled: November 1, 1993Date of Patent: December 26, 1995Assignee: Gas Research InstituteInventors: Meilin Liu, Ashok V. Joshi, Yousheng Shen, Kevin Krist, Anil V. Virkar
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Patent number: 5183801Abstract: Disclosed is a stable bismuth oxide composition having excellent oxygen ion conductivity comprising: from 50 to 90 mole % Bi.sub.2 O.sub.3, from 10 to 40 mole % of a rare earth oxide, such as yttria; and from 0.1 to 10 mole % of an oxide compound, such as ZrO.sub.2 or ThO.sub.2. The composition retains its oxygen ion transport capabilities even after prolonged annealing.Type: GrantFiled: April 9, 1991Date of Patent: February 2, 1993Assignee: Gas Research InstituteInventors: Anil V. Virkar, Kuan-Zong Fung
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Patent number: 5006494Abstract: Disclosed is a stable bismuth oxide composition having excellent oxygen ion conductivity comprising: from 50 to 90 mole % Bi.sub.2 O.sub.3, from 10 to 40 mole % of a rare earth oxide, such as yttria; and from 0.1 to 10 mole % g an oxide compound, such as ZrO.sub.2 or ThO.sub.2. The composition retains its oxygen ion transport capabilities even after prolonged annealing.Type: GrantFiled: April 24, 1989Date of Patent: April 9, 1991Assignee: Gas Research InstituteInventor: Anil V. Virkar
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Patent number: 5002911Abstract: A ceramic comprising a matrix of Al.sub.2 O.sub.3, ZrO.sub.2 (partially or fully stabilized) or mixtures of Al.sub.2 O.sub.3 and ZrO.sub.2 with strontium aluminate plate-shaped grains distributed throughout the matrix results in a ceramic with high toughness, high strength and good hardness. SrO/Al.sub.2 O.sub.3 molar ratios between 0.02 and 0.20 result in in-situ formation of plate-shaped grains approximately 0.5 .mu.m in thickness and 5.0 .mu.m in breadth in tetragonal zirconia polycrystalline ceramic matrices. The in-situ formation of strontium aluminates allows high volume loading of platelets to occur and high toughness is achieved without the loss of strength. High alumina compositions have the added benefit of higher strength, lower thermal expansion, higher modulus and higher thermal conductivity than zirconia ceramics with comparable toughness.Type: GrantFiled: April 7, 1989Date of Patent: March 26, 1991Assignee: Cerametec, Inc.Inventors: Roger L. K. Matsumoto, Anil V. Virkar, Raymond A. Cutler
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Patent number: 4895776Abstract: An improved high temperature electrochemical cell employing a molten alkali metal anolyte, a solid ceramic electrolyte containing mobile alkali metal ions, and a molten sulfur/selenium catholyte is disclosed.Type: GrantFiled: October 26, 1988Date of Patent: January 23, 1990Assignee: Ceramatec, Inc.Inventors: Anil V. Virkar, Gerald R. Miller, James R. Rasmussen
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Patent number: 4876148Abstract: Ceramic bodies having a balanced overall stress pattern in which are present individual stress zones of compressive and tensile stresses and the techniques for forming said bodies are disclosed. The bodies are formed by having slightly different compositional patterns from one zone to another whereby during cooling there is a differential volumetric expansion or contraction in one zone as compared to an adjacent zone. The volumetric expansion or contraction is caused by a material which undergoes a phase transformation during the cooling from the sintering temperatures utilized to sinter the ceramic body, whereby such phase transformation is accompanied by a volumetric change.Type: GrantFiled: June 30, 1987Date of Patent: October 24, 1989Assignee: Ceramatec, Inc.Inventor: Anil V. Virkar