Patent US4294892A successfully refreshed from Google Patents.
US4294892A
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Method for the operation of a fuel cell
Assignee: Electrochemische Energieconversie NV
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Filing: 1980-05-01
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Granted: 1981-10-13
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Expires: 2000-05-01
Abstract
Abstract An improved method for operating a fuel cell employing porous gas diffusion electrodes. The method provides for the regeneration of the electrode by keeping the oxidizing or reducing gas temporarily at a reduced concentration level while substantially maintaining the pressure on the gas in situ of the electrode and while continuing power offtake at least for the period during which the concentration level is reduced.
Inventors
- 👤 Marinus Alfenaar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:15
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/04; H01M8/04223; H01M8/04238; H01M8/04298; H01M8/043; H01M8/04303; H01M8/02; H01M8/0202; H01M8/0258; H01M8/04228; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
102 words
A method for operating a fuel cell with a porous gas diffusion electrode to which an oxidizing or reducing gas is fed, wherein the concentration level of the oxidizing or reducing gas, calculated as molecular oxygen or hydrogen respectively, in the gas phase in situ of the electrode in question is temporarily brought to a reduced level the terminal voltage being reduced to below 10% of its original value, the overall pressure of the gas phase in situ of this electrode being substantially maintained and the power offtake is continued for at least the period during which the concentration level is reduced.
Claim 2
Independent Claim
102 words
A method for operating a fuel cell with a porous gas diffusion electrode to which an oxidizing or reducing gas is fed, wherein the concentration level of the oxidizing or reducing gas, calculated as molecular oxygen or hydrogen respectively, in the gas phase in situ of the electrode in question is temporarily brought to a reduced level the terminal voltage being reduced to below 10% of its original value, the overall pressure of the gas phase in situ of this electrode being substantially maintained and the power offtake is continued for at least the period during which the concentration level is reduced.
Claim 3
Dependent Claim
47 words
A method according to claim 1 wherein the porous gas diffusion electrode is regularly regenerated by maintaining the concentration of the oxidizing or reducing gas in the gas phase in situ of the electrode at given intervals and for a given time at the said reduced level.
Claim 4
Dependent Claim
37 words
A method according to claim 2 wherein during operation of the fuel cell the step of reducing the concentration level occurs for a period of time ranging from about 1 to about 30 minutes every 10-200 hours.
Claim 5
Dependent Claim
13 words
A method according to claim 1 wherein the fuel cell becomes shut down.
Claim 6
Independent Claim
50 words
A method according to any of claims 1-4 wherein the concentration of the oxidizing or reducing gas in the gas phase in situ of the said electrode is decreased by replacing the normal feed gas by a feed gas with a reduced concentration level of the oxidizing or reducing gas.
Claim 7
Dependent Claim
27 words
A method according to claim 5 wherein the feed gas having the reduced concentration level is a gas that is inert under the conditions of the reaction.
Claim 8
Dependent Claim
12 words
A method according to claim 6 wherein the inert gas is nitrogen.
Claim 9
Independent Claim
52 words
A method according to any of claims 1-3 wherein the resistance of the gas discharge line on the cathode or anode side of the fuel cell is increased without at least proportionally increasing the resistance of the gas feed line in question, the composition of the gas feed not substantially being changed.
Claim 10
Independent Claim
48 words
A method according to any of claims 1, 2 or 3, wherein the electrode is comprised of a flat gas diffusion electrode including at least a catalytically active layer containing a catalytically active metal, carbon and a polymeric bonding agent and is porous to gas and the electrolyte.
Claim 11
Dependent Claim
20 words
A method according to claim 1 where operation is as a gas diffusion cathode wherein the oxidizing gas comprises oxygen.
Claim 12
Dependent Claim
15 words
A method according to claim 10 wherein air is employed as the normal feed gas.
Claim 13
Dependent Claim
21 words
A method according to claim 1 wherein the operation is as a gas diffusion anode with the reducing gas comprising hydrogen.
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) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |