Patent US4043933A successfully refreshed from Google Patents.
US4043933A
Expired / Lapsed
US
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Method of fabricating a fuel cell electrode
Assignee: RTX Corp
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Filing: 1976-06-15
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Granted: 1977-08-23
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Expires: 1996-06-15
Abstract
Abstract A method of fabricating a fuel cell electrode comprising an electrocatalyst and binder wherein the colloidal chemistry of the aqueous catalyst and the binder suspension are controlled during the deposition of the catalyst/binder onto an electrode substrate. Control is by addition of acids, bases, or salts to an aqueous suspension of binder and catalyst to adjust the pH to within certain ranges to form a flocculate. The flocculate is then fabricated into an electrode. The catalyst/binder distribution within the electrode and electrochemical performance, including decay characteristics, of the electrode are improved.
Inventors
- 👤 Richard D. Breault
- 👤 Richard P. Harding
- 👤 Fred S. Kemp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:28
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/8663; H01M4/8668; H01M4/88; H01M4/8825; H01M4/8828; H01M4/8835; H01M4/886; H01M4/8878; H01M4/8882; H01M4/8885; H01M4/90; H01M4/92; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
65 words
The method of constructing a stabilized fuel cell electrode comprising the steps of forming a uniform aqueous suspension of electrocatalyst particles and hydrophobic polymer particles; adjusting the pH of said suspension to a range of from pH 1.5 to pH 6, or from a range of pH 10 to pH 12 to form an electrocatalyst/polymer flocculate; and fabricating said flocculate into a fuel cell electrode.
Claim 2
Independent Claim
65 words
The method of constructing a stabilized fuel cell electrode comprising the steps of forming a uniform aqueous suspension of electrocatalyst particles and hydrophobic polymer particles; adjusting the pH of said suspension to a range of from pH 1.5 to pH 6, or from a range of pH 10 to pH 12 to form an electrocatalyst/polymer flocculate; and fabricating said flocculate into a fuel cell electrode.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein the hydrophobic polymer is polytetrafluoroethylene.
Claim 4
Dependent Claim
10 words
The method of claim 2 wherein the electrocatalyst is platinum.
Claim 5
Dependent Claim
19 words
The method of claim 2 wherein the pH is adjusted to substantially a pH of 2 using an acid.
Claim 6
Dependent Claim
19 words
The method of claim 2 wherein the pH is adjusted to a pH of substantially 11 using a base.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein the pH is adjusted to a range of from pH 1.5 to pH 4.0.
Claim 8
Dependent Claim
18 words
The method of claim 2 wherein said step of fabricating includes spraying said flocculate onto a conductive support.
Claim 9
Dependent Claim
18 words
The method of claim 2 wherein said step of fabricating includes filtering said flocculate onto a conductive support.
Claim 10
Dependent Claim
11 words
The method of claim 4 wherein the acid is phosphoric acid.
Claim 11
Dependent Claim
11 words
The method of claim 5 wherein the base is ammonium hydroxide.
Claim 12
Independent Claim
104 words
The method of constructing a fuel cell electrode comprising the steps of forming a uniform aqueous suspension of platinum supported on carbon particles and particles of polytetrafluoroethylene stabilized with a surfactant; adjusting the pH of said suspension to a range of from pH 1.5 to pH 4.0, or from a range of pH 10 to pH 12 to form a supported platinum/polytetrafluoroethylene flocculate; and fabricating said flocculate into a fuel cell electrode including the steps of applying said flocculate to a conductive support to form a catalyst/polymer layer on said support and heating said electrode to remove the surfactant and sinter the catalyst/polymer layer.
Claim 13
Independent Claim
104 words
The method of constructing a fuel cell electrode comprising the steps of forming a uniform aqueous suspension of platinum supported on carbon particles and particles of polytetrafluoroethylene stabilized with a surfactant; adjusting the pH of said suspension to a range of from pH 1.5 to pH 4.0, or from a range of pH 10 to pH 12 to form a supported platinum/polytetrafluoroethylene flocculate; and fabricating said flocculate into a fuel cell electrode including the steps of applying said flocculate to a conductive support to form a catalyst/polymer layer on said support and heating said electrode to remove the surfactant and sinter the catalyst/polymer layer.
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) | 1980-08-22 | 1981-02-21 | 1981-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-22 | 1985-02-21 | 1985-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-22 | 1989-02-21 | 1989-08-23 | $7700.00 | Window Closed / Lapsed |