US4287232A
Expired / Lapsed
US
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Dry floc method for making an electrochemical cell electrode
Assignee: RTX Corp
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Filing: 1978-06-28
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Granted: 1981-09-01
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Expires: 1998-06-28
Abstract
Abstract A method for making an electrochemical cell electrode involves depositing a layer of dry carbon/hydrophobic polymer floc powder on the surface of a substrate by dispersing the powder as a cloud in a chamber over the substrate and pulling the powder onto the substrate by drawing a vacuum under the substrate. The electrode is subsequently compacted and sintered. Typically the carbon component of the floc is catalyzed, such as with platinum. Thus, the method is for applying a catalyst layer on an electrode substrate. The method is particularly adapted to the high speed manufacture of electrodes.
Inventors
- 👤 Glen J. Goller
- 👤 Joseph R. Salonia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:03
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/88; H01M4/8803; H01M4/8807; B; B05; B05D; B05D1/00; B05D1/16; H01M4/8825; H01M4/886; H01M4/8878; H01M4/8882; H01M4/8885; H01M4/8896; B05D3/00; B05D3/04; B05D3/0493; H01M8/00; H01M8/02; H01M8/0202; H01M8/023; H01M8/0234; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
129 words
A method for making an electrochemical cell electrode comprising the steps of: applying a uniform layer of dry, powdered, carbon/hydrophobic polymer floc on the surface of a porous electrode substrate with virtually no floc within the pores of the substrate by positioning the substrate under a chamber having a bottom edge wherein the said bottom edge of the chamber fits against the edge of the substrate, dispersing the floc as a cloud of powder in the chamber over said surface of said positioned substrate and pulling the floc onto said surface by drawing a continuous vacuum under the substrate until the desired amount of powder has been deposited, wherein said substrate is graphitized carbon paper made from carbon fibers; compacting the applied floc layer; and, sintering the compacted layer.
Claim 2
Independent Claim
129 words
A method for making an electrochemical cell electrode comprising the steps of: applying a uniform layer of dry, powdered, carbon/hydrophobic polymer floc on the surface of a porous electrode substrate with virtually no floc within the pores of the substrate by positioning the substrate under a chamber having a bottom edge wherein the said bottom edge of the chamber fits against the edge of the substrate, dispersing the floc as a cloud of powder in the chamber over said surface of said positioned substrate and pulling the floc onto said surface by drawing a continuous vacuum under the substrate until the desired amount of powder has been deposited, wherein said substrate is graphitized carbon paper made from carbon fibers; compacting the applied floc layer; and, sintering the compacted layer.
Claim 3
Dependent Claim
12 words
The method according to claim 1 wherein the hydrophobic polymer is PTFE.
Claim 4
Dependent Claim
18 words
The method according to claim 1 wherein the electrode substrate has an open porosity of at least 80%.
Claim 5
Dependent Claim
21 words
The method according to claim 1 wherein the particle size of the floc powder is no greater than about ten microns.
Claim 6
Dependent Claim
15 words
The method according to claim 1 wherein the carbon particles in the floc are precatalyzed.
Claim 7
Dependent Claim
18 words
The method according to claim 1 wherein the floc is a precatalyzed carbon/PTFE floc, the catalyst comprising platinum.
Claim 8
Dependent Claim
22 words
The method according to claim 1 wherein the mean particle size of the powdered floc is no greater than about one micron.
Claim 9
Independent Claim
150 words
A method for making an electrochemical cell electrode comprising the steps of: forming a co-suspension of carbon particles and hydrophobic polymer particles; floccing the co-suspension; drying the floc so produced and reducing it to a powder; applying a uniform layer of the powder on the surface of a porous electrode substrate with virtually no floc within the pores of the substrate by positioning the substrate under a chamber having a bottom edge wherein the said bottom edge of the chamber fits against the edge of the substrate, dispersing the floc as a cloud of powder in the chamber over said surface of said positioned substrate and pulling the floc onto said surface by drawing a continuous vacuum under the substrate until the desired amount of powder has been deposited, wherein said substrate is graphitized carbon paper made from carbon fibers; compacting the applied floc layer; and, sintering the compacted layer.
Claim 10
Independent Claim
150 words
A method for making an electrochemical cell electrode comprising the steps of: forming a co-suspension of carbon particles and hydrophobic polymer particles; floccing the co-suspension; drying the floc so produced and reducing it to a powder; applying a uniform layer of the powder on the surface of a porous electrode substrate with virtually no floc within the pores of the substrate by positioning the substrate under a chamber having a bottom edge wherein the said bottom edge of the chamber fits against the edge of the substrate, dispersing the floc as a cloud of powder in the chamber over said surface of said positioned substrate and pulling the floc onto said surface by drawing a continuous vacuum under the substrate until the desired amount of powder has been deposited, wherein said substrate is graphitized carbon paper made from carbon fibers; compacting the applied floc layer; and, sintering the compacted layer.
Claim 11
Dependent Claim
23 words
The method according to claim 8 wherein the dry floc powder particles have a mean particle size of about one micron or less.
Claim 12
Dependent Claim
17 words
The method according to claim 9 wherein the polymer comprises PTFE and the carbon particles are precatalyzed.
Claim 13
Dependent Claim
18 words
The method according to claim 9 wherein the electrode substrate has an open porosity of at least 80%.
Claim 14
Dependent Claim
37 words
The method according to claim 10 wherein the catalyst is platinum, said dry floc powder includes a small amount of phosphoric acid, and before compacting said floc layer moisture accumulated therein is removed by heating said layer.
Claim 15
Dependent Claim
18 words
The method according to claim 9 wherein the maximum particle size of the floc is about ten microns.
Claim 16
Dependent Claim
47 words
The method according to claim 1 or 8 wherein the step of dispersing the floc in the chamber includes introducing a predetermined amount of the floc into the chamber and maintaining the vacuum until all of said predetermined amount of floc has been drawn to the surface.
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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) | 1984-08-31 | 1985-03-02 | 1985-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-31 | 1989-03-02 | 1989-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-31 | 1993-03-02 | 1993-09-01 | $7700.00 | Window Closed / Lapsed |