HIGH TEMPERATURE GAS SEALS

• US 20040104544A1
• Filed: 07/23/2003
• Published: 06/03/2004
• Est. Priority Date: 07/23/2002
• Status: Abandoned Application

• Current Assignee: Fuelcell Energy Ltd.
• Original Assignee: Fuelcell Energy Ltd.
• Inventors: LI, Jian, BRULE, Robert, FAN, Jen-Jung, GHOSH, Debabrata
• Application Number:
  US10/604,460
• Publication Number:
  US 20040104544A1
• Time in Patent Office: Days
• US Class Current: 277/650
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3232 Titanium oxides or titanates, e.g. rutile or anatase
• CPC Class Codes: C04B 2235/3244 Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/401 Alkaline earth metals
• CPC Class Codes: C04B 2235/402 Aluminium
• CPC Class Codes: C04B 2235/404 Refractory metals
• CPC Class Codes: C04B 2235/428 Silicon
• CPC Class Codes: C04B 2235/5224 Alumina or aluminates
• CPC Class Codes: C04B 2235/5236 Zirconia
• CPC Class Codes: C04B 2235/524 Non-oxidic, e.g. borides, carbides, silicides or nitrides
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/6025 Tape casting, e.g. with a doctor blade
• CPC Class Codes: C04B 35/053 Fine ceramics
• CPC Class Codes: C04B 35/111 Fine ceramics
• CPC Class Codes: C04B 35/14 based on silica
• CPC Class Codes: C04B 35/46 based on titanium oxides or titanates containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49
• CPC Class Codes: C04B 35/486 Fine ceramics
• CPC Class Codes: C04B 35/58014 based on titanium nitrides, e.g. TiAlON
• CPC Class Codes: C04B 35/80 : Fibres, filaments, whiskers, platelets, or the like
• CPC Class Codes: H01M 2008/1293 : Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 8/0271 : Sealing or supporting means around electrodes, matrices or membranes
• CPC Class Codes: H01M 8/0276 : Sealing means characterised by their form H01M8/0273 takes precedence
• CPC Class Codes: H01M 8/0282 : Inorganic material
• CPC Class Codes: H01M 8/0286 : Processes for forming seals
• CPC Class Codes: H01M 8/2425 : High-temperature cells with solid electrolytes
• CPC Class Codes: Y02E 60/50 : Fuel cells

Abstract

A flexible seal for use in a solid oxide fuel cell stack is formed from a ceramic fibre matrix impregnated with a plurality of metallic or semi-metallic particles which are then converted to a corresponding ceramic particle, such as by oxidation. The seal may be formed by dipping the fibre matrix into a slurry, suspension or sol-gel of the particles in an alcohol, and then firing the seal to oxidize the metal particles. The seal may also be formed by tape casting a slurry formed from metallic or semi-metallic particles, ceramic fibres and/or ceramic particles.

Claims

1. A method of forming a high-temperature gas seal comprising the steps of:

(a)combining a ceramic component with a reactive component;

(b)installing the seal in between first and second contact surfaces; and

(c)converting the reactive component to a corresponding ceramic material in situ.

2. The method of claim 1 wherein the reactive component bonds to itself, to the ceramic component and to the first and second contact surfaces during conversion.

3. The method of claim 1 wherein the ceramic component comprises a ceramic felt or paper or ceramic particles and wherein the reactive component comprises metal particles or metal precursors and wherein the ceramic particles and the metal particles are impregnated within the ceramic felt or paper by dipping the felt or paper into a slurry comprising the ceramic particles and the metal particles.

4. The method of claim 2 wherein the metal particles is selected from the group consisting of aluminium, titanium, silicon, magnesium and zirconium.

5. The method of claim 1 wherein the conversion of the reactive component comprises oxidation of the reactive component with a volumetric increase.

6. The method of claim 1 wherein the reactive component and the ceramic component are mixed in a suitable slurry formulation and the seal is formed by tape-casting or slip casting.

7. The method of claim 3 wherein the metal particles comprise aluminium and the ceramic component comprises alumina.

8. A high-temperature gas seal formed by the method of claim 1, 2, 3, 4, 5, 6 or 7.

9. A seal comprising a reactive component and a ceramic component, wherein the reactive component may be converted to a corresponding ceramic material in situ.

10. The seal of claim 9 wherein the reactive component comprises metallic, semi-metallic or metal precursor particles and wherein the ceramic component comprises ceramic particles.

11. The seal of claim 10 wherein the reactive component particles are selected from the group consisting of aluminium, zirconium, yttrium, titanium, calcium, magnesium and silicon, or mixtures thereof.

12. The seal of claim 11 wherein the reactive component particles comprise aluminium particles and wherein the ceramic component comprises alumina particles.

13. The seal of claim 12 wherein the ceramic component further comprises alumina fibres.

14. A seal comprising a reactive component and a ceramic component, wherein the reactive component comprises a ceramic material which has been converted from a metallic, semi-metallic or metal precursor material to a corresponding ceramic material in situ.