US4695518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon carbide matrix for fuel cells
Assignee: RTX Corp
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Filing: 1985-04-10
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Granted: 1987-09-22
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Expires: 2005-04-10
Abstract
Abstract A matrix for holding the electrolyte within a phosphoric acid fuel cell is made from silicon carbide and a binder of polyestersulfone. Preferably the matrix consists of 10-20 weight percent polyethersulfone with a balance of silicon carbide. The matrix has improved strength, wettability and bubble pressure compared to the best known prior art matrix.
Inventors
- 👤 John C. Trocciola
- 👤 Joseph Powers
- 👤 Ronald G. Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:44
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/02; H01M8/0289; H01M8/0293; H01M2300/00; H01M2300/0002; H01M2300/0005; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
85 words
A fuel cell comprising: a pair of spaced apart gas diffusion electrodes; a porous electrolyte retaining matrix confined in the space between said electrodes, said matrix having a porosity of at least 38 percent and consisting essentially of 70 to 90 weight percent silicon carbide and a balance of hydrophilic polyethersulfone as a binder; and phosphoric acid electolyte disposesd within said matrix, wherein said matrix has the characteristic that it remains physically intact for at least 17,000 hours of fuel cell operation at 375° F.
Claim 2
Dependent Claim
85 words
A fuel cell comprising: a pair of spaced apart gas diffusion electrodes; a porous electrolyte retaining matrix confined in the space between said electrodes, said matrix having a porosity of at least 38 percent and consisting essentially of 70 to 90 weight percent silicon carbide and a balance of hydrophilic polyethersulfone as a binder; and phosphoric acid electolyte disposesd within said matrix, wherein said matrix has the characteristic that it remains physically intact for at least 17,000 hours of fuel cell operation at 375° F.
Claim 3
Dependent Claim
18 words
The fuel cell according to claim 1 wherein said matrix includes between 10 and 20 weight percent polyethersulfone.
Claim 4
Dependent Claim
17 words
The fuel cell according to claim 1 wherein said polyethersulfone consists essentially of the repeating unit ##STR5##
Claim 5
Dependent Claim
20 words
The fuel cell according to claim 3 wherein said polyethersulfone has a number average molecular weight of at least 17,000.
Claim 6
Dependent Claim
20 words
The fuel cell according to claim 3 wherein said polyethersulfone has a number average molecular weight of at least 25,000.
Claim 7
Dependent Claim
93 words
A fuel cell comprising; a pair of spaced apart gas diffusion electrodes; a porous electrolyte retaining matrix confined in the space between said electrodes, said matrix consisting essentially of silicon carbide particles with a balance of between 10 and 20 weight percent hydrophilic polyethersulfone, said polyethersulfone consisting essentially of the repeating unit ##STR6## said matrix having a porosity of least 38 percent; and phosphoric acid electrolyte disposed within said matrix, wherein said matrix has the characteristic that it remains physically intact for at least 17,000 hours of fuel cell operation at 375° F.
Claim 8
Dependent Claim
93 words
A fuel cell comprising; a pair of spaced apart gas diffusion electrodes; a porous electrolyte retaining matrix confined in the space between said electrodes, said matrix consisting essentially of silicon carbide particles with a balance of between 10 and 20 weight percent hydrophilic polyethersulfone, said polyethersulfone consisting essentially of the repeating unit ##STR6## said matrix having a porosity of least 38 percent; and phosphoric acid electrolyte disposed within said matrix, wherein said matrix has the characteristic that it remains physically intact for at least 17,000 hours of fuel cell operation at 375° F.
Claim 9
Dependent Claim
60 words
An electrolyte retaining matrix for a fuel cell, said matrix having a porosity of at least 38 percent and consisting of 80 to 90 weight percent silicon carbide particles and a balance of polyethersulfone, said polyethersulfone coating said silicon carbide particles and being uniformly dispersed throughout said matrix, said polyethersulfone having a number average molecular weight of at least 25,000.
Claim 10
Dependent Claim
60 words
An electrolyte retaining matrix for a fuel cell, said matrix having a porosity of at least 38 percent and consisting of 80 to 90 weight percent silicon carbide particles and a balance of polyethersulfone, said polyethersulfone coating said silicon carbide particles and being uniformly dispersed throughout said matrix, said polyethersulfone having a number average molecular weight of at least 25,000.
Claim 11
Dependent Claim
16 words
The matrix according to claim 7 wherein said polyethersulfone consists essentially of the repeating unit: ##STR7##
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-21 | 1991-03-23 | 1991-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-21 | 1995-03-23 | 1995-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-21 | 1999-03-23 | 1999-09-22 | $7700.00 | Window Closed / Lapsed |