Patent US4219611A successfully refreshed from Google Patents.
US4219611A
Expired / Lapsed
US
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Fuel cell electrolyte reservoir layer and method for making
Assignee: RTX Corp
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Filing: 1979-07-30
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Granted: 1980-08-26
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Expires: 1999-07-30
Abstract
Abstract A porous graphite reservoir layer for retaining electrolyte within a fuel cell is improved by coating the pore surfaces of the reservoir layer with wettable, particulate amorphous carbon. Preferably the amorphous carbon particles are colloidal and have a mean pore size considerably smaller than the pore size of the body which they coat. This coated reservoir retains its hydrophilic properties for an extended period of time.
Inventors
- 👤 Richard D. Breault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:14
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/08; H01M4/00; H01M4/86; H01M4/96; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
49 words
A method for increasing the length of time a hydrophilic, porous graphite body remains hydrophilic when used as a reservoir layer for accommodating electrolyte volume changes within a phosphoric acid fuel cell comprising the steps of: coating the pore surfaces of said graphite body with particulate, wettable, amorphous carbon.
Claim 2
Independent Claim
49 words
A method for increasing the length of time a hydrophilic, porous graphite body remains hydrophilic when used as a reservoir layer for accommodating electrolyte volume changes within a phosphoric acid fuel cell comprising the steps of: coating the pore surfaces of said graphite body with particulate, wettable, amorphous carbon.
Claim 3
Dependent Claim
34 words
The method according to claim 1 wherein said amorphous carbon particles are colloidal and have a pore size at least two orders of magnitude less than the pore size of the uncoated graphite body.
Claim 4
Dependent Claim
25 words
The method according to claim 2 wherein the coating is applied so thinly it has virtually no effect on the porosity of the graphite body.
Claim 5
Dependent Claim
48 words
The method according to claim 2 wherein said graphite body comprises a mat of graphitized carbon fibers and said step of coating includes saturating the void volume of said mat with a stable liquid dispersion of said amorphous carbon and subsequently removing the liquids from said saturated body.
Claim 6
Dependent Claim
20 words
The method according to claim 4 wherein the weight percent of soilds in said liquid dispersion is at least 0.10.
Claim 7
Dependent Claim
20 words
The method according to claim 5 wherein said amorphous carbon has an oxygen content of at least 1.0 weight percent
Claim 8
Dependent Claim
19 words
The method according to claim 4 wherein the graphitized carbon fibers of said mat have been resin bonded together.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-26 | 1984-02-25 | 1984-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-26 | 1988-02-25 | 1988-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-26 | 1992-02-25 | 1992-08-26 | $7700.00 | Window Closed / Lapsed |