| Patent application number | Description | Published |
|---|
| 20090004531 | Fuel cell stack having multiple parallel fuel cells - A fuel cell stack comprising a plurality of serially-connected fuel cell stages, each stage comprising a plurality of fuel cells arranged electrically in parallel such that each stage has the voltage drop of a single fuel cell but current output defined by the total cell area. The assembled stack thus comprises essentially a plurality of internal fuel cell stacks arranged in parallel, each stack having the same voltage, and the stack currents being additive. The total voltage is the same as for a prior art stack of the same number of stages, but the current and hence the power output is multiplied over that of a single-cell stack by the number of internal fuel cell stacks. Preferably, each stage is a cassette including a plurality of windows for receiving the individual fuel cell units; a plurality of anode and cathode interconnects; and a single separator plate. | 01-01-2009 |
| 20090004532 | Dummy cassettes for a solid oxide fuel cell stack - A fuel cell stack assembly comprising a plurality of serially-assembled fuel cell stages formed as individual cassette units, wherein at least one of the first and last cassettes, and preferably both, is a dummy cassette assembled with a metal blank in place of the fuel cell, which metal blank preferably is formed integrally with a dummy picture frame element. A dummy cassette contains an interconnect, flow blocking anode spacers, metal contact paste, and a separator plate to assure electrical conductivity and structural integrity in the assembled fuel cell stack. Providing the dummy cassettes corrects a known problem of underperformance of the end fuel cell cassettes which limits the performance of the entire stack. | 01-01-2009 |
| 20090004544 | Glass seal with ceramic fiber for a solid-oxide fuel cell stack - A glass ceramic composition for sealing adjacent metal cassettes in an SOFC stack. The seal composition comprises an alumina-silicate glass ceramic matrix and a ceramic fiber aggregate dispersed in the matrix. Preferably, the fiber is selected from the group consisting of zirconium oxide fiber, alumina fiber, and combinations thereof. Preferably, the fiber is present at 1-60 weight percent with respect to the weight of glass ceramic, preferably about 30 weight percent. Preferably, the zirconia is stabilized by up to about 10% yttria. Alumina fiber may substitute for a portion of the zirconia fiber. Preferably, a green seal is die cut from a green tape sheet formed by extrusion of a slurry comprising water and a latex binder. The green seal is sintered during the final SOFC stack assembly process to form the final stack seal. | 01-01-2009 |
| 20090004545 | Solid bonded interconnect system in a lightweight solid oxide fuel cell stack - An interconnect system for connecting adjacent fuel cells in a fuel cell stack. The system comprises five elements: a separator plate to provide an anode gas flow space when joined to a mating cell frame; a first metal interconnect disposed between the separator plate and the anode surface; a nickel oxide paste applied in a pattern over the surface of the anode and adjacent surface of the separator plate which when sintered results in a conductive layer bonded to the anode and to the separator plate; a second metal interconnect disposed between the cathode surface of the cell and the separator plate of the adjacent cell cassette; and a silver-containing paste applied over the surface of the cathode and the separator plate which when sintered results in a conductive layer bonded to the cathode and to the separator plate. | 01-01-2009 |
| 20090220813 | Braze alloy containing particulate material - A minimum joint thickness can be assured by incorporating beads or particles having a diameter corresponding to the joint thickness desired and which are infusible at the brazing temperature. Preferably such particles are formed of high-melting metals, metal oxides, ceramics, or cermets and are mixed into the alloy paste prior to fusing. In a preferred embodiment, the particle-containing paste is mixed with a non-flux carrier to facilitate application to the elements to be brazed. Exemplary application methods may include painting, rolling, screening, or extrusion dispensing. Brazing alloys in accordance with the invention are useful in bonding ceramics to ceramics, ceramics to metals, and metals to metals. | 09-03-2009 |
| 20100081032 | Glass Seal Containing Zirconia Powder and Fiber for a Solid Oxide Fuel Cell Stack - A glass ceramic composition for sealing adjacent metal cassettes in an SOFC stack. The seal composition comprises an alumina-silicate glass ceramic matrix or a matrix of Zr2 and a ceramic fiber aggregate and non-fibrous zirconia dispersed in the matrix. Preferably, the fiber is selected from the group consisting of zirconium oxide fiber, alumina fiber, and combinations thereof. Preferably, the fiber is present at 1-60 weight percent with respect to the weight of glass ceramic, preferably about 30 weight percent. Preferably, the zirconia fiber is stabilized by up to about 10% yttria. Alumina fiber may substitute for a portion of the zirconia fiber. Preferably, the non-fibrous zirconia is present at about 5 weight percent and is also stabilized. | 04-01-2010 |
| 20100143760 | INHIBITOR FOR PREVENTION OF BRAZE MIGRATION IN SOLID OXIDE FUEL CELLS - During manufacture of an SOFC assembly, an inhibitor is included to prevent migration of silver braze during subsequent use of the SOFC assembly. The inhibitor may take any of several forms, either individually or in combination. Inhibitors comprehended by the present invention include, but are not limited to: a) a mechanical barrier that can be printed or dispensed onto one or more SOFC stack elements around the braze areas to prevent mechanically-driven migration; b) an electrically insulating feature in the electrolyte or interlayer over the electrolyte layer in the seal margins to prevent electrical potential-driven migration; and 3) chemical modification of the braze itself as by addition of an alloying metal such as palladium. | 06-10-2010 |
| 20100143762 | Method for Improving Robustness of Solid Oxide Fuel Cell Stacks - A method for forming a solid oxide fuel cell stack from a plurality of individual solid oxide fuel cells, wherein the anodes of the solid oxide fuel cells are infiltrated by one or more materials for making the anodes less sensitive to sulfur poisoning and/or less subject to carbon degradation and/or for improving the electrochemical performance of the stack, the method comprising the steps of oxidizing the anodes of the individual solid oxide fuel cells before forming a stack, building a solid oxide fuel cell stack with all of the anodes in an oxidized state, reducing all of the anodes, and then infiltrating all of the anodes with at least one of the materials. | 06-10-2010 |
| 20100143763 | Laminated Plate Repeating Fuel Cell Unit For an SOFC Stack - An improved SOFC repeating fuel cell unit comprising three flat plates and a cell retainer. The three flat plates are metallurgically joined (brazed or laser welded) into a subassembly to which is added the fuel cell and cell retainer (which may also be joined as a second subassembly). Each flat plate performs a specific set of functions and can be optimized for those functions. Since the plates are flat and designed to overlap in loaded areas, the fuel cell unit is not prone to dimensional collapse which eliminates the internal reinforcements of the prior art design. The cell retainer is formed to provide a self-locating and locking feature for the fuel cell and decouples thermal stresses from the thin ceramic fuel cell. | 06-10-2010 |
| 20100233564 | Fuel Cell Stack Including Non-Fuel Cell Cassette - A fuel cell stack is disclosed including a non-fuel cell cassette having temperature sensing elements disposed therein. The temperature sensing elements are disposed in one or more void spaces in the non-fuel cell cassette, which void spaces are connected to openings in the side of the non-fuel cell cassette for lead wires to communicate information from the temperature sensing elements to components outside of the fuel cell stack. | 09-16-2010 |
| 20110129754 | Structure for Forming a Solid Oxide Fuel Cell Stack - A solid oxide fuel cell system comprising a plurality of electrochemically active fuel cell cassettes connected in electrical series and bonded together by a plurality of glass seals to form a fuel cell stack. A dummy cassette containing a thermocouple is disposed within the fuel cell stack. Each cassette may have at least one alignment tab for receiving a rod to maintain stack alignment during sintering, and each fuel cell cassette has electrical terminals extending from a side of the stack for performance testing. The distribution manifold is attached to stack, and a spring subassembly is disposed against the stack and is attached to the manifold by tie rods to maintain a compressive load on the stack through sintering and subsequent use to prevent unloading and rupture of the glass seals. | 06-02-2011 |
| 20110159173 | CONDUCTIVE COATING FOR SOLID OXIDE FUEL CELLS - A method of manufacturing an electrically conductive interconnect for a solid oxide fuel cell stack, including the steps of (a) making a metal substrate having a first surface configured for electrical contact with an anode of the solid oxide fuel cell stack and a second surface configured for electrical contact with a cathode of the solid oxide fuel cell stack; (b) depositing a layer comprising metallic cobalt over at least a portion of at least one of the first and second surfaces; and (c) subjecting the metallic cobalt to reducing conditions, thereby causing at least a portion of the metallic cobalt to diffuse into the metal substrate. | 06-30-2011 |
