Other

Presidio Components. Inc.

Mary Trinh

Alan D Devoe

A method of fabricating a ceramic tube with electrodes thereon suitable for use as a tubular reaction chamber for a fuel cell. In one embodiment, the method includes wrapping a first electrode material around a mandrel, then wrapping a green ceramic material over the first electrode material, and then wrapping a second electrode material over the green ceramic material. The wrapped layers are laminated together, and then removed from the mandrel and sintered, in either sequence, to produce the laminated ceramic tube having an inner first electrode and an outer second electrode. Alternatively, a first electrode tube is provided in place of the mandrel and around which the green ceramic material is wrapped. The outer second electrode may be produced by wrapping a second electrode material around the green ceramic material, before or after laminating, or by printing the electrode material onto the sintered ceramic tube. The present invention further provides a method of making a ceramic tube in which a sacrificial organic material is first wrapped around the mandrel to a desired thickness prior to wrapping the green ceramic material to increase the green material thickness. During sintering, the organic material is burned away leaving only a laminated ceramic tube, optionally with electrodes thereon.

Method of making laminate thin-wall ceramic tubes and said tubes with electrodes, particularly for solid oxide fuel cells

Very thin cast ceramic tape, preferably approximately 12 &mgr;m in thickness, is wrapped, preferably in a reversing spiral or helix, around a mandrel, preferably a mandrel made of steel and coated with a wax releasing agent, for so many times, preferably five or greater, as achieves a desired thickness of a tube wall, preferably about 100 &mgr;m. The green ceramic tube is then laminated in a pressure laminator, preferably a hydrostatic laminator at 3000 to 5000 psi, linking polymer chains between each ceramic layer, cross-linking polymer chains within each ceramic layer, and densifying the produced ceramic laminate tube by reducing porosity. By varying the wraps, wrapping and/or mandrel surface, high quality thin-wall laminate ceramic tubes having any of (i) external reinforcement windings as enhance burst strength, (ii) thickened end regions as facilitate mounting while reducing breakage, and/or (iii) internal features, including baffles, as desirably induce turbulence in longitudinal gas flow, may all readily be fabricated, including in an automated process.

Laminate thin-wall ceramic tubes, including with integral stress wrappings, thickened ends and/or internal baffles, particularly for solid oxide fuel cells

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San Diego, CA, United States of America

Mary Trinh