US4781727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for gas sealing of phosphoric acid-type fuel cell
Assignee: New Energy and Industrial Technology Development Organization
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Filing: 1988-01-20
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Granted: 1988-11-01
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Expires: 2008-01-20
Abstract
Abstract The invention relates to an improvement of the gas sealing at the periphery of the electrode base and separator which constitute the fuel cell. Provided herein is a method for sealing the gas of a phosphoric acid-type fuel cell which comprises filling the pores in the porous material periphery of the cell constituents with fine particles of at least one of silicon carbide and silicon nitride which have undergone surface oxidation treatment, and causing particles to expand in volume through the reaction of the surface oxide of the particles with hot phosphoric acid that yields phosphate compounds, thereby clogging the pores.
Inventors
- 👤 Kenro Mitsuda
- 👤 Hisashi Shiota
- 👤 Kenzo Takahashi
- 👤 Kozo Shimamoto
- 👤 Toshiaki Murahashi
- 👤 Ikuyuki Hirata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:51
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/02; H01M8/0271; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49108; Y10T29/4911; Y10T29/49115
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
74 words
A method for sealing the gas of a phosphoric acid-type fuel cell which comprises filling the pores in the porous material periphery of the cell constituents with fine particles of at least one of silicon carbide and silicon nitride which have undergone surface oxidation treatment, and causing particles to expand in volume through the reaction of the surface oxide of the particles with hot phosphoric acid that yields phosphate compounds, thereby clogging the pores.
Claim 2
Independent Claim
74 words
A method for sealing the gas of a phosphoric acid-type fuel cell which comprises filling the pores in the porous material periphery of the cell constituents with fine particles of at least one of silicon carbide and silicon nitride which have undergone surface oxidation treatment, and causing particles to expand in volume through the reaction of the surface oxide of the particles with hot phosphoric acid that yields phosphate compounds, thereby clogging the pores.
Claim 3
Dependent Claim
35 words
A method as claimed in claim 1 wherein the treatment of the surface-oxidized fine particles with hot phosphoric acid is accomplished by impregnating the fuel cell with phosphoric acid before operation of the fuel cell.
Claim 4
Dependent Claim
35 words
A method as claimed in claim 1 wherein the treatment of the surface-oxidized fine particles with hot phosphoric acid is accomplished by impregnating the fuel cell with phosphoric acid during operation of the fuel cell.
References Cited (Backward Citations)
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US4017664A
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US4529671A
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US4623415A
Cited
US4517260A
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US4695518A
Cited
US4687715A
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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) | 1991-11-01 | 1992-05-02 | 1992-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-01 | 1996-05-02 | 1996-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-01 | 2000-05-02 | 2000-11-01 | $7700.00 | Window Closed / Lapsed |