Abstract: The invention relates to perovskite oxide electrode materials in which one or more of the elements Mg, Ni, Cu, and Zn are present as minority components that enhance electrochemical performance, as well as electrode products with these compositions and methods of making the electrode materials. Such electrodes are useful in electrochemical system applications such as solid oxide fuel cells, ceramic oxygen generation systems, gas sensors, ceramic membrane reactors, and ceramic electrochemical gas separation systems.

Abstract: Amperometric ceramic electrochemical cells comprise, in one embodiment, an electrolyte layer, a sensing electrode layer, and a counter electrode layer, wherein the cell is operable in an oxidizing atmosphere and under an applied bias to exhibit enhanced reduction of oxygen molecules at the sensing electrode in the presence of one or more target gases such as nitrogen oxides (NOX) or NH3 and a resulting increase in oxygen ion flux through the cell. In another embodiment, amperometric ceramic electrochemical cells comprise an electrolyte layer comprising a continuous network of a first material which is ionically conducting at an operating temperature of about 200 to 550° C.; a counter electrode layer comprising a continuous network of a second material which is electrically conductive at an operating temperature of about 200 to 550° C.; and a sensing electrode layer comprising a continuous network of a third material which is electrically conductive at an operating temperature of about 200 to 550° C.

Abstract: Electrode materials systems for planar solid oxide fuel cells with high electrochemical performance including anode materials that provide exceptional long-term durability when used in reducing gases and cathode materials that provide exceptional long-term durability when used in oxygen-containing gases. The anode materials may comprise a cermet in which the metal component is a cobalt-nickel alloy. These anode materials provide exceptional long-term durability when used in reducing gases, e.g., in SOFCs with sulfur contaminated fuels. The cermet also may comprise a mixed-conducting ceria-based electrolyte material. The anode may have a bi-layer structure. A cerium oxide-based interfacial layer with mixed electronic and ionic conduction may be provided at the electrolyte/anode interface.

Abstract: Electrode materials systems for planar solid oxide fuel cells with high electrochemical performance including anode materials that provide exceptional long-term durability when used in reducing gases and cathode materials that provide exceptional long-term durability when used in oxygen-containing gases. The cathode materials comprise zinc-doped lanthanum strontium ferrite (LSZF) or an alternative ferrite, cobaltite or nickelate ceramic electrode material. The cathode material also may comprise a mixed-conducting ceria-based electrolyte material, a palladium dopant, or a combination of these. The cathode may have a bi-layer structure. A ceramic-based interfacial layer may be provided at the electrolyte/cathode interface. The multilayer cathode system and its palladium doped cathode material exhibit a high degree of tolerance to chromium contamination during operation with metallic interconnect materials.

Abstract: A hydrogen sensitive composite sensing material based on cerium oxide with or without additives to enhance sensitivity to hydrogen, reduce cross-sensitivities to interfering gases, or lower the operating temperature of the sensor, and a device incorporating these hydrogen sensitive composite materials including a support, electrodes applied to the support, and a coating of hydrogen sensitive composite material applied over the electroded surface. The sensor may have in integral heater. The sensor may have a tubular geometry with the heater being inserted within the tube. A gas sensor device may include a support, electrodes applied to the support, and a dual sensor element to cancel unwanted effects on baseline resistance such as those resulting from atmospheric temperature changes. The hydrogen sensitive composite material or other gas sensitive materials may be used in the dual element gas sensor device.

Abstract: Aqueous coating slurries useful in depositing a dense coating of a ceramic electrolyte material (e.g., yttrium-stabilized zirconia) onto a porous substrate of a ceramic electrode material (e.g., lanthanum strontium manganite or nickel/zirconia) and processes for preparing an aqueous suspension of a ceramic electrolyte material and an aqueous spray coating slurry including a ceramic electrolyte material. The invention also includes processes for depositing an aqueous spray coating slurry including a ceramic electrolyte material onto pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Abstract: A fuel cell assembly includes a plurality of opposing fuel cell stacks. Each of the fuel stacks has a plurality of fuel cells in which each fuel cell has an anode, a cathode, and an electrolyte. The fuel cell assembly further includes a spacing member disposed between the fuel cell stacks thereby defining a fluidic cavity.

Abstract: A sensor and method of use for detection of low levels of carbon monoxide in gas mixtures. The approach is based on the change in an electrical property (for example: resistance) that occurs when carbon monoxide is selectively absorbed by a film of copper chloride (or other metal halides). The electrical property change occurs rapidly with both increasing and decreasing CO contents, varies with the amount of CO from the gas stream, and is insensitive to the presence of hydrogen. To make a sensor using this approach, the metal halide film will deposited onto an alumina substrate with electrodes. The sensor may be maintained at the optimum temperature with a thick film platinum heater deposited onto the opposite face of the substrate. When the sensor is operating at an appropriate (and constant) temperature, the magnitude of the electrical property measured between the interdigital electrodes will provide a measure of the carbon monoxide content of the gas.

Abstract: The invention relates to perovskite oxide electrode materials in which one or more of the elements Mg, Ni, Cu, and Zn are present as minority components that enhance electrochemical performance, as well as electrode products with these compositions and methods of making the electrode materials. Such electrodes are useful in electrochemical system applications such as solid oxide fuel cells, ceramic oxygen generation systems, gas sensors, ceramic membrane reactors, and ceramic electrochemical gas separation systems.

Abstract: The invention relates to perovskite oxide electrode materials in which one or more of the elements Mg, Ni, Cu, and Zn are present as minority components that enhance electrochemical performance, as well as electrode products with these compositions and methods of making the electrode materials. Such electrodes are useful in electrochemical system applications such as solid oxide fuel cells, ceramic oxygen generation systems, gas sensors, ceramic membrane reactors, and ceramic electrochemical gas separation systems.

Abstract: Processes for preparing aqueous suspensions of a nanoscale ceramic electrolyte material such as yttrium-stabilized zirconia. The invention also includes a process for preparing an aqueous coating slurry of a nanoscale ceramic electrolyte material. The invention further includes a process for depositing an aqueous spray coating slurry including a ceramic electrolyte material on pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Abstract: A method of making ceramic electrode materials comprising intimate mixtures of two or more components, including at least one nanoscale ionically conducting ceramic electrolyte material (e.g., yttrium-stabilized zirconia, gadolinium-doped ceria, samarium-doped ceria, etc.) and at least one powder of an electrode material, which may be an electrically conducting ceramic electrode material (e.g., lanthanum strontium manganite, praseodymium strontium manganese iron oxide, lanthanum strontium ferrite, lanthanum strontium cobalt ferrite, etc.) or a precursor of a metallic electrode material (e.g., nickel oxide, copper oxide, etc.). The invention also includes anode and cathode coatings and substrates for solid oxide fuel cells prepared by this method.

Abstract: Processes for preparing aqueous suspensions of a nanoscale ceramic electrolyte material such as yttrium-stabilized zirconia. The invention also includes a process for preparing an aqueous coating slurry of a nanoscale ceramic electrolyte material. The invention further includes a process for depositing an aqueous spray coating slurry including a ceramic electrolyte material on pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Abstract: A ceramic material in the lithium aluminosilicate (LAS) system, having a negative coefficient of thermal expansion and improved mechanical properties, the material having a stoichiometric composition of Li.sub.1+X AlSiO.sub.4+X/2, where 0.ltoreq.x.ltoreq.0.1. The ceramic material can be made by mixing silicon and aluminum oxides (SiO.sub.2 and Al.sub.2 O.sub.5) with lithium carbonate (Li.sub.2 CO.sub.3) and calcining the mixture. Alternatively, the ceramic material can be made by mixing silicon oxide (SiO.sub.2), lithium aluminate (LiAlO.sub.2), and, if desired, lithium carbonate (Li.sub.2 CO.sub.3), and calcining the mixture. Alternatively, the ceramic material can be made by mixing spodumene (an inexpensive mineral with a nominal composition of LiAlSi.sub.2 O.sub.6), lithium aluminate (LiAlO.sub.2), and the required amounts of other constituents (Li.sub.2 CO.sub.3, Al.sub.2 O.sub.3, or SiO.sub.2), and calcining the mixture.

Abstract: A continuous process for making a crystalline ceramic powder having a perovskite structure, ABO.sub.3, comprising:a. preparing a first acidic aqueous solution containing one or more elements that are insoluble precursor elements capable of forming the perovskite structure;b. preparing a second basic solution containing a sufficient concentration of hydroxide to precipitate the elements in step (a);c. mixing the first acidic solution with the second basic solution to precipitate a substantially pure mixture of hydroxides;d. washing the precipitate to remove hydroxide and salt impurities;e. forming a slurry of oxides or hydroxides of one or more of the elements that are soluble precursor elements capable of forming in the perovskite structure, and heating the slurry to a temperature sufficient to dissolve the soluble oxides or hydroxides of the soluble precursor elements;f. redispersing the washed precipitate and heating to the temperature of the soluble oxides or hydroxides of step (e);g.

Abstract: A dielectric ceramic composition comprising a sintered mixture represented by the formula:Bi.sub.2-x (Zn.sub.(2+y)/3 Nb.sub.4/3)O.sub.7-3x/2+y/3where: 0.240.ltoreq.x.ltoreq.0.333, and 0.120.ltoreq.y.ltoreq.0.300; and a dielectric composition given by the formula:(Bi.sub.1-z Ca.sub.z).sub.2-x (Zn.sub.(2+y)/3 Nb.sub.4/3)O.sub.7-3x/2+y/3+xz/2-zwhere: 0.ltoreq.x.ltoreq.0.667, 0.ltoreq.y.ltoreq.0.300, and 0<z.ltoreq.0.200; substitutions for Bi can be selected from the group consisting of Ca, Sr, Ba, Y, Pb, Cd, La and other rare earth oxides having atomic numbers 58-71 of the periodic table; substitutions for Zn can be selected from the group consisting of Mg, Ca, Co, Mn, Ni, and Cu; and substitutions for Nb can be selected from the group consisting of Ti, Zr, Hf, and Ta; wherein the substitutions comprise less than 20 mol % based on the Bi, Zn, and Nb content respectively.Typically, BZN and calcium-modified BZN ceramics are prepared by the initial preparation of a ZnNb.sub.2 O.sub.6 precursor; mixing of ZnNb.

Abstract: A method for producing a thin film of a ferroelectric perovskite material having the steps of providing a first substrate; depositing a first layer of a sol-gel perovskite precursor material wherein the crystallization of this precursor material to the pervoskite phase is insensitive to the first substrate; depositing a second layer of a sol-gel perovskite precursor material wherein the crystallization is sensitive to the first substrate; and heat-treating the deposited layers to form ferroelectric perovskites. A heat treatment step to form perovskites may optionally follow the deposition of the first layer. The first layer of sol-gel perovskite precursor material is selected to produce a perovskite upon heat treatment of: lead titanate (PbTiO.sub.3), or strontium titanate (SrTiO.sub.3). The second layer of sol-gel perovskite precursor material is selected to produce a perovskite upon heat treatment of: lead zirconate titanate (Pb(Zr,Ti)O.sub.3), lead zirconate (PbZrO.sub.

Abstract: A process for making a crystalline ceramic powder having a perovskite structure, ABO.sub.