High temperature gas seals

• US 6,902,798 B2
• Filed: 08/17/2001
• Issued: 06/07/2005
• Est. Priority Date: 08/18/2000
• Status: Expired due to Term

• Current Assignee: Versa Power Systems Ltd
• Original Assignee: Fuelcell Energy Ltd.
• Inventors: Thompson, Scott, Ghosh, Debabrata
• Primary Examiner(s): Morris, Terrel
• Assistant Examiner(s): Vo, Hai
• Application Number:
  US09/931,415
• Publication Number:
  US 20020024185A1
• Time in Patent Office: 1,390 Days
• Field of Search: 428/311.11, 428/311.51, 428/312.6, 428/317.9, 428/920, 428/312.8
• US Class Current: 428/317.9
• CPC Class Codes: C04B 14/22 Glass ; Devitrified glass
• CPC Class Codes: C04B 14/30 Oxides other than silica ferrites C04B14/363
• CPC Class Codes: C04B 14/303 Alumina
• CPC Class Codes: C04B 14/4618 Oxides
• CPC Class Codes: C04B 14/4625 Alumina
• CPC Class Codes: C04B 14/4637 Zirconia or zircon
• CPC Class Codes: C04B 2111/00853 in electrochemical cells or batteries, e.g. fuel cells
• CPC Class Codes: C04B 30/02 containing fibrous materials
• CPC Class Codes: H01M 8/0271 Sealing or supporting means around electrodes, matrices or membranes
• CPC Class Codes: H01M 8/0282 Inorganic material
• CPC Class Codes: H01M 8/0297 Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other H01M8/0271 takes precedence
• CPC Class Codes: H01M 8/1231 with both reactants being gaseous or vaporised
• CPC Class Codes: H01M 8/2425 High-temperature cells with solid electrolytes
• CPC Class Codes: H01M 8/2432 Grouping of unit cells of planar configuration
• CPC Class Codes: H01M 8/2483 characterised by internal manifolds
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 428/92 Fire or heat protection feature
• CPC Class Codes: Y10T 428/249962 Void-containing component has a continuous matrix of fibers only [e.g., porous paper, etc.]
• CPC Class Codes: Y10T 428/249964 Fibers of defined composition
• CPC Class Codes: Y10T 428/249969 Of silicon-containing material [e.g., glass, etc.]
• CPC Class Codes: Y10T 428/24997 : Of metal-containing material
• CPC Class Codes: Y10T 428/249986 : Void-containing component contains also a solid fiber or solid particle

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.

Claims

1. A seal for use in a solid oxide fuel cell comprising a matrix of ceramic fibres and a plurality of solid particles impregnated within the matrix and interspersed between the ceramic fibres, wherein the fibres and solid particles are unsintered and wherein the fibres and particles combine to form a flexible and compressible seal which is substantially but not hermetically gas-tight, wherein a substantial portion of the particles have a particle size less than about 1 micron, and wherein the solid particles comprise a first portion and a second portion, wherein the average particle size of the first portion is larger than the average particle size of the second portion.

2. The seal of claim 1 wherein the first portion has an average particle size of about 0.50 micron and the second portion has an average particle size of about 0.17 micron or less.

3. The seal of claim 1 wherein the fibres are randomly oriented.

4. The seal of claim 1 wherein the seal is compressed prior to installation into a fuel cell stack.

5. The seal of claim 1 wherein the solid particles comprise ceramic particles.

6. The seal of claim 1 wherein some or all of the ceramic fibres comprise alumina, zirconia, titania, magnesia or silica.

7. The seal of claim 6 wherein the fibres comprise alumina and the particles comprise alumina or zirconia.

8. The seal of claim 1 wherein some or all of the ceramic particles comprise alumina, zirconia, titania, magnesia or silica.