Patent US4115528A successfully refreshed from Google Patents.
US4115528A
Expired / Lapsed
US
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Method for fabricating a carbon electrode substrate
Assignee: RTX Corp
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Filing: 1977-08-15
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Granted: 1978-09-19
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Expires: 1997-08-15
Abstract
Abstract A method for fabricating porous carbon sheet material and in particular for fabricating porous carbon fuel cell electrode substrates comprises coating carbon fibers with a mixture of furfuryl alcohol and a catalyst which polymerizes furfuryl alcohol, forming the fibers into a mat or sheet of the desired size and thickness, heating the mat to polymerize the furfuryl alcohol and to cure the resin so formed, and further heating the mat to carbonize the resin. Phosphoric acid is the preferred polymerization catalyst when the sheet material is to be used as a fuel cell electrode substrate. The method produces electrode substrates which are highly porous yet strong and which are also corrosion resistant, thermally conductive and electrically conductive.
Inventors
- 👤 Larry G. Christner
- 👤 Dennis C. Nagle
- 👤 Paul R. Watson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:08
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/96; D; D01; D01F; D01F11/00; D01F11/10; D01F11/12; D01F11/125; D01F11/14; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22; D01F9/225; H01M4/02; H01M4/64; H01M4/66; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
89 words
A method for fabricating a porous carbon sheet comprising the steps of: coating chopped carbon fibers with a low viscosity mixture of at least 70% by weight furfuryl alcohol, 0.25-5%, by weight, of an aqueous solution of 85% phosphoric acid or an equivalent amount of phosphoric acid, and a balance of water; forming a mat of said coated fibers; polymerizing the furfuryl alcohol and curing the mat by heating the mat to a temperature between 50°-200° C.; and carbonizing the cured mat by heating to at least 1500° C.
Claim 2
Independent Claim
89 words
A method for fabricating a porous carbon sheet comprising the steps of: coating chopped carbon fibers with a low viscosity mixture of at least 70% by weight furfuryl alcohol, 0.25-5%, by weight, of an aqueous solution of 85% phosphoric acid or an equivalent amount of phosphoric acid, and a balance of water; forming a mat of said coated fibers; polymerizing the furfuryl alcohol and curing the mat by heating the mat to a temperature between 50°-200° C.; and carbonizing the cured mat by heating to at least 1500° C.
Claim 3
Dependent Claim
30 words
The method according to claim 1 wherein the step of polymerizing the furfuryl alcohol and curing the mat is accomplished by heating the mat to a temperature between 100°-150° C.
Claim 4
Dependent Claim
24 words
The method according to claim 1 wherein the step of polymerizing the furfuryl alcohol and curing the mat is done in an oxidizing atmosphere.
Claim 5
Dependent Claim
15 words
The method according to claim 1 wherein said mixture is at least 85% furfuryl alcohol.
Claim 6
Independent Claim
120 words
A method for fabricating an electrochemical cell electrode substrate comprising the steps of: coating chopped carbon fibers with a low viscosity mixture of at least 70% furfuryl alcohol, 0.25-5%, by weight, of an aqueous solution of 85% phosphoric acid or an equivalent amount of phosphoric acid, and a balance of water, said step of coating including dispersing said fibers in a bath of said mixture; forming a mat of said coated fibers, including permitting said dispersed fibers to settle onto a screen disposed in said bath; polymerizing the furfuryl alcohol and curing the mat by heating the mat to a temperature between 50°-200° C. in an oxidizing atmosphere; and carbonizing the cured mat by heating to at least 1500° C.
Claim 7
Independent Claim
120 words
A method for fabricating an electrochemical cell electrode substrate comprising the steps of: coating chopped carbon fibers with a low viscosity mixture of at least 70% furfuryl alcohol, 0.25-5%, by weight, of an aqueous solution of 85% phosphoric acid or an equivalent amount of phosphoric acid, and a balance of water, said step of coating including dispersing said fibers in a bath of said mixture; forming a mat of said coated fibers, including permitting said dispersed fibers to settle onto a screen disposed in said bath; polymerizing the furfuryl alcohol and curing the mat by heating the mat to a temperature between 50°-200° C. in an oxidizing atmosphere; and carbonizing the cured mat by heating to at least 1500° C.
Claim 8
Dependent Claim
34 words
The method according to claim 5 wherein said mixture includes at least 85% by weight furfuryl alcohol, and said step of polymerizing and curing the mat includes heating to a temperature between 100°-150° C.
Claim 9
Dependent Claim
21 words
The method according to claim 5 wherein said step of carbonizing includes heating the cured mat to at least 1900° C.
Claim 10
Dependent Claim
18 words
The method according to claim 5 wherein the carbon fibers are less than about 2 inches in length.
Claim 11
Independent Claim
129 words
A method for fabricating a fuel cell electrode substrate comprising the steps of: coating chopped carbon pitch fibers which are less than about two inches in length with a mixture of at least 85% furfuryl alcohol, 0.25-5%, by weight, of an aqueous solution of 85% phosphoric acid or an equivalent amount of phosphoric acid, and a balance of water, said step of coating including dispersing said fibers in a bath of said mixture; forming a mat of said coated fibers, including permitting said dispersed fibers to settle onto a screen disposed in said bath; polymerizing the furfuryl alcohol and fully curing the mat by heating the mat to a temperature between 100°-150° C. in an oxidizing atmosphere; and carbonizing the cured mat by heating to at least 1900° C.
Claim 12
Independent Claim
129 words
A method for fabricating a fuel cell electrode substrate comprising the steps of: coating chopped carbon pitch fibers which are less than about two inches in length with a mixture of at least 85% furfuryl alcohol, 0.25-5%, by weight, of an aqueous solution of 85% phosphoric acid or an equivalent amount of phosphoric acid, and a balance of water, said step of coating including dispersing said fibers in a bath of said mixture; forming a mat of said coated fibers, including permitting said dispersed fibers to settle onto a screen disposed in said bath; polymerizing the furfuryl alcohol and fully curing the mat by heating the mat to a temperature between 100°-150° C. in an oxidizing atmosphere; and carbonizing the cured mat by heating to at least 1900° C.
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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) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |