Abstract: A flexible seal for use in a solid oxide fuel cell stack is formed from a fiber matrix impregnated with a plurality of solid particles. The fibers and particles are preferably ceramic and may be formed from alumina or zirconia. The seal may be formed by dipping the fiber matrix into a slurry of the particles in an alcohol, drying the seal and precompressing prior to installation in the fuel cell stack.

Abstract: A solid oxide fuel cell stack incorporates metallic interconnects each of which includes a fuel intake manifold, a fuel exhaust manifold, an oxidant intake manifold and an oxidant exhaust manifold. The fuel side of the interconnect defines a fuel flow field surrounded by a continuous sealing surface and in fluid communication with the fuel intake and exhaust manifold. The oxidant side of the interconnect defines an oxidant flow field surrounded by a continuous sealing surface and in fluid communication with the oxidant intake and exhaust manifolds. The interconnect may be fabricated by brazing together three stainless steel plates having overlapping openings to permit the exclusionary flow of fuel and oxidant through the interconnect.

Abstract: A solid oxide fuel cell stack includes a thermally responsive compression element. The compression element extends between the top and bottom plates of the stack and has an overall coefficient of thermal expansion which is substantially the same or less than the composite coefficient of thermal expansion of the stack itself. The compression element may be elongated and include a lower rod, an upper sleeve and an intermediate expansion member which are concentrically arranged. The expansion member bears on shoulders formed on the lower rod and upper sleeve to provide a compressive force at elevated temperatures, if the expansion member has a higher coefficient of thermal expansion than the lower rod and upper sleeve.

Abstract: A fuel cell unit includes a cassette holder for a ceramic fuel cell element sandwiched between interconnects of a novel design. The cassette holder isolates the cell from the surrounding interconnect by means of a pliant seal within a rigid frame, thereby reducing the possibility of breakage of the brittle cells. The cassettes are assembled between an upper and lower interconnect to isolate the upper face of the cell from the lower face of the cell. A fuel cell unit includes an upper and lower interconnect containing a cassette. A fuel cell stack is formed from a plurality of fuel cell units.