US4017664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon carbide electrolyte retaining matrix for fuel cells
Assignee: RTX Corp
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Filing: 1975-09-02
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Granted: 1977-04-12
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Expires: 1995-09-02
Abstract
Abstract In a fuel cell utilizing an acid electrolyte, such as H3PO4, the electrolyte retaining matrix is made from silicon carbide. The silicon carbide has been found to be virtually inert to H3PO4 at fuel cell operating temperatures and provides all the other necessary and desirable matrix properties. This matrix is expected to have a life of at least 40,000 hours under normal fuel cell operating conditions.
Inventors
- 👤 Richard D. Breault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:41
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/02; H01M8/0289; H01M8/0293; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
42 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 and extending therebetween, and comprising at least 90% silicon carbide; and phosphoric acid electrolyte disposed within said matrix.
Claim 2
Dependent Claim
42 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 and extending therebetween, and comprising at least 90% silicon carbide; and phosphoric acid electrolyte disposed within said matrix.
Claim 3
Dependent Claim
15 words
The fuel cell according to claim 1 wherein said matrix includes up to 10% binder.
Claim 4
Dependent Claim
14 words
The fuel cell according to claim 2 wherein said binder is a fluorocarbon polymer.
Claim 5
Dependent Claim
12 words
The fuel cell according to claim 2 wherein said binder is polytetrafluoroethylene.
Claim 6
Dependent Claim
14 words
The fuel cell according to claim 2 wherein said binder is fluorinated ethylene propylene.
Claim 7
Dependent Claim
15 words
The fuel cell according to claim 2 wherein said matrix comprises 95%- 98% silicon carbide.
Claim 8
Dependent Claim
14 words
The fuel cell according to claim 6 wherein said binder is a fluorocarbon polymer.
Claim 9
Dependent Claim
16 words
The fuel cell according to claim 7 wherein said polymer is polytetrafluoroethylene or fluorinated ethylene propylene.
Claim 10
Dependent Claim
46 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 and and extending therebetween consisting essentially of 90%-100% silicon carbide particles and 0-10% binder; and phosphoric acid electrolyte disposed within said matrix.
Claim 11
Dependent Claim
46 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 and and extending therebetween consisting essentially of 90%-100% silicon carbide particles and 0-10% binder; and phosphoric acid electrolyte disposed within said matrix.
Claim 12
Dependent Claim
22 words
The fuel cell according to claim 9 wherein said matrix consists essentially of 95%-98% silicon carbide particles and 2%-5% fluorocarbon polymer binder.
Claim 13
Dependent Claim
17 words
The fuel cell according to claim 10 wherein said particles are less than 25 microns in size.
Claim 14
Dependent Claim
17 words
The fuel cell according to claim 11 wherein said particles are less than 10 microns in size.
Claim 15
Dependent Claim
58 words
A fuel cell comprising: a pair of spaced apart gas diffusion electrodes; an electrolyte retaining matrix confined in the space between said electrodes and extending therebetween, said matrix consisting essentially of 95%-98% silicon carbide particles and 2%-5% of either polytetrafluoroethylene or fluorinated ethylene propylene as a binder for said particles; and phosphoric acid electrolyte disposed within said matrix.
Claim 16
Dependent Claim
58 words
A fuel cell comprising: a pair of spaced apart gas diffusion electrodes; an electrolyte retaining matrix confined in the space between said electrodes and extending therebetween, said matrix consisting essentially of 95%-98% silicon carbide particles and 2%-5% of either polytetrafluoroethylene or fluorinated ethylene propylene as a binder for said particles; and phosphoric acid electrolyte disposed within said matrix.
Claim 17
Dependent Claim
17 words
The fuel cell according to claim 13 wherein said particles are less than 10 microns in size.
Claim 18
Independent Claim
88 words
A method for making a phosphoric acid fuel cell, said fuel cell including a pair of spaced apart gas diffusion electrodes separated by and each in contact with a matrix, including the step of: making said matrix by 1. forming an aqueous suspension including at least nine parts silicon carbide for every one part binder; 2. applying said suspension to the surface of at least one of said electrodes to form a layer thereon; 3. drying and sintering said layer; and 4. impregnating said matrix with phosphoric acid.
Claim 19
Independent Claim
88 words
A method for making a phosphoric acid fuel cell, said fuel cell including a pair of spaced apart gas diffusion electrodes separated by and each in contact with a matrix, including the step of: making said matrix by 1. forming an aqueous suspension including at least nine parts silicon carbide for every one part binder; 2. applying said suspension to the surface of at least one of said electrodes to form a layer thereon; 3. drying and sintering said layer; and 4. impregnating said matrix with phosphoric acid.
Claim 20
Dependent Claim
22 words
The method according to claim 15 wherein said aqueous suspension includes 9.5-9.8 parts silicon carbide for every 0.2-0.5 parts fluorocarbon polymer binder.
Claim 21
Dependent Claim
22 words
The method according to claim 15 wherein said silicon carbide in said suspension consists of particles less than 25 microns in size.
Claim 22
Dependent Claim
22 words
The method according to claim 15 wherein said silicon carbide in said suspension consists of particles less than 10 microns in size.
Claim 23
Independent Claim
100 words
A method for making a phosphoric acid fuel cell, said fuel cell including a pair of spaced apart gas diffusion electrodes separated by and each in contact with a matrix, including the step of: making said matrix by 1. forming an aqueous suspension including 9.5-9.8 parts silicon carbide for every 0.2-0.5 parts fluorocarbon polymer binder, said silicon carbide consisting of particles less than 10 microns in size; 2. applying said suspension to the surface of at least one of said electrodes to form a layer thereon; 3. drying and sintering said layer; and 4. impregnating said matrix with phosphoric acid.
Claim 24
Independent Claim
100 words
A method for making a phosphoric acid fuel cell, said fuel cell including a pair of spaced apart gas diffusion electrodes separated by and each in contact with a matrix, including the step of: making said matrix by 1. forming an aqueous suspension including 9.5-9.8 parts silicon carbide for every 0.2-0.5 parts fluorocarbon polymer binder, said silicon carbide consisting of particles less than 10 microns in size; 2. applying said suspension to the surface of at least one of said electrodes to form a layer thereon; 3. drying and sintering said layer; and 4. impregnating said matrix with phosphoric acid.
Claim 25
Dependent Claim
109 words
In the process of generating electricity with a fuel cell, said fuel cell including a pair of spaced apart gas diffusion electrodes separated by and each in contact with a matrix filled with phosphoric acid electrolyte and means defining a fuel gas chamber on the non-matrix side of one of said electrode elements and an oxidant gas chamber on the non-matrix side of the other of said electrode elements, including the steps of: connecting said electrode elements across a load; passing a fuel through said fuel gas chamber; and passing an oxidant through said oxidant gas chamber, wherein said matrix consists essentially of 90-100% silicon carbide and 10-0% binder.
Claim 26
Dependent Claim
109 words
In the process of generating electricity with a fuel cell, said fuel cell including a pair of spaced apart gas diffusion electrodes separated by and each in contact with a matrix filled with phosphoric acid electrolyte and means defining a fuel gas chamber on the non-matrix side of one of said electrode elements and an oxidant gas chamber on the non-matrix side of the other of said electrode elements, including the steps of: connecting said electrode elements across a load; passing a fuel through said fuel gas chamber; and passing an oxidant through said oxidant gas chamber, wherein said matrix consists essentially of 90-100% silicon carbide and 10-0% binder.
Claim 27
Dependent Claim
16 words
The process of generating electricity according to claim 20 wherein said binder is a fluorocarbon polymer.
Claim 28
Dependent Claim
24 words
The process of generating electricity according to claim 20 wherein said matrix consists essentially of 95%-98% silicon carbide particles and 2%-5% fluorocarbon polymer binder.
Claim 29
Dependent Claim
19 words
The process of generating electricity according to claim 20 wherein said particles are less than 25 microns in size.
Claim 30
Dependent Claim
19 words
The process of generating electricity according to claim 20 wherein said particles are less than 10 microns in size.
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) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |