US4189526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metal/oxygen cells and method for optimizing the active life properties thereof
Assignee: Duracell Inc USA
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Filing: 1978-05-05
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Granted: 1980-02-19
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Expires: 1998-05-05
Abstract
Abstract Metal/oxygen cells such as zinc/air cells are provided with optimum active life characteristics by interposing, on the air side of the cell, an oxygen diffusivity-limiting membrane, such as, for example, sintered polytetrafluoroethylene, so that no more oxygen is received than is needed for the current rate required for the intended application.
Inventors
- 👤 John W. Cretzmeyer
- 👤 Hans R. Espig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:43
CPC Classifications
H; H01; H01M; H01M12/00; H01M12/04; H01M12/06; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
105 words
A gas depolarized electrochemical cell comprising a cell casting having means allowing oxygen ingress therein at a level capable of sustaining a current in excess of 800 microamps, an anode and a cathode disposed in the casing, a separator interposed between said anode and cathode, an electrolyte positioned on the anode side of the separator, an oxygen distribution means providing oxygen across at least the majority of the cathode area, and an oxygen diffusivity-limiting membrane positioned between said cathode and said oxygen distribution means, said membrane limiting oxygen ingress to the cathode to less than the level required to sustain a current of 800 microamps.
Claim 2
Dependent Claim
105 words
A gas depolarized electrochemical cell comprising a cell casting having means allowing oxygen ingress therein at a level capable of sustaining a current in excess of 800 microamps, an anode and a cathode disposed in the casing, a separator interposed between said anode and cathode, an electrolyte positioned on the anode side of the separator, an oxygen distribution means providing oxygen across at least the majority of the cathode area, and an oxygen diffusivity-limiting membrane positioned between said cathode and said oxygen distribution means, said membrane limiting oxygen ingress to the cathode to less than the level required to sustain a current of 800 microamps.
Claim 3
Dependent Claim
34 words
The cell of claim 1 wherein said oxygen diffusivity-limiting membrane provides oxygen ingress at a rate sufficient to sustain a current drain rate of about 1 to about 35 microamps/cm 2 of cathode area.
Claim 4
Dependent Claim
31 words
The cell of claim 1 wherein said oxygen diffusivity-limiting membrane is a member selected from the group consisting of polyethylene, sintered polytetrafluoroethylene, unsintered polytetrafluoroethylene filled with carbon and cellulose acetate butyrate.
Claim 5
Dependent Claim
13 words
The cell of claim 3 wherein said oxygen diffusivity-limiting membrane is sintered polytetrafluoroethylene.
Claim 6
Dependent Claim
21 words
The cell of claim 1 wherein said oxygen diffusivity-limiting membrane has a thickness of from about 0.5 to about 6 mils.
Claim 7
Dependent Claim
15 words
The cell of claim 1 wherein said oxygen distribution means comprises a porous absorbent layer.
Claim 8
Dependent Claim
13 words
The cell of claim 6 wherein said porous absorbent layer is filter paper.
Claim 9
Dependent Claim
16 words
The cell of claim 1 wherein said cathode includes on the air side a hydrophobic film.
Claim 10
Dependent Claim
12 words
The cell of claim 8 wherein said hydrophobic film is unsintered polytetrafluoroethylene.
Claim 11
Dependent Claim
10 words
The cell of claim 1 wherein the anode is zinc.
Claim 12
Dependent Claim
37 words
The cell of claim 1 for use in an application requiring a particular current drain rate wherein said membrane limits oxygen ingress to the cathode to substantially that level required to sustain said particular current drain rate.
Claim 13
Independent Claim
126 words
A method of limiting oxygen ingress to the cathode of a gas depolarized electrochemical cell so as to optimize its active life, the cell including a cell casing having means allowing oxygen ingress therein at a level capable of sustaining a current in excess of 800 microamps, an anode and a cathode disposed in the casing, a separator interposed between said anode and cathode, an electrolyte positioned on the anode side of the separator, an oxygen distribution means providing oxygen across at least the majority of the cathode area, which method comprises positioning an oxygen diffusivity-limiting membrane between said cathode and said oxygen distribution means, said membrane limiting oxygen ingress to the cathode to less than the level required to sustain a current of 800 microamps.
Claim 14
Independent Claim
126 words
A method of limiting oxygen ingress to the cathode of a gas depolarized electrochemical cell so as to optimize its active life, the cell including a cell casing having means allowing oxygen ingress therein at a level capable of sustaining a current in excess of 800 microamps, an anode and a cathode disposed in the casing, a separator interposed between said anode and cathode, an electrolyte positioned on the anode side of the separator, an oxygen distribution means providing oxygen across at least the majority of the cathode area, which method comprises positioning an oxygen diffusivity-limiting membrane between said cathode and said oxygen distribution means, said membrane limiting oxygen ingress to the cathode to less than the level required to sustain a current of 800 microamps.
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) | 1983-02-18 | 1983-08-20 | 1984-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-18 | 1987-08-20 | 1988-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-18 | 1991-08-20 | 1992-02-19 | $7700.00 | Window Closed / Lapsed |