US4448858A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemically rechargeable battery
Assignee: California Institute of Technology
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Filing: 1983-03-17
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Granted: 1984-05-15
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Expires: 2003-03-17
Abstract
Abstract Batteries (50) containing oxidized, discharged metal electrodes such as an iron-air battery are charged by removing and storing electrolyte in a reservoir (98), pumping fluid reductant such as formalin (aqueous formaldehyde) from a storage tank (106) into the battery in contact with the surfaces of the electrodes. After sufficient iron hydroxide has been reduced to iron, the spent reductant is drained, the electrodes rinsed with water from rinse tank (102) and then the electrolyte in the reservoir (106) is returned to the battery. The battery can be slowly electrically charged when in overnight storage but can be quickly charged in about 10 minutes by the chemical procedure of the invention.
Inventors
- 👤 James E. Graf
- 👤 John J. Rowlette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:58
CPC Classifications
H; H01; H01M; H01M6/00; H01M6/50; H01M6/5077; H01M12/00; H01M12/08; H01M50/00; H01M50/70; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
A system for recharging a metal-oxidant gas battery having an electrolyte inlet and an electrolyte outlet comprising: a fluid circuit for connection to said inlet and outlet containing: electrolyte storage means; reservoir means containing a supply of fluid reducing agent; pump means for flowing the electrolyte into and out of the battery and for flowing the fluid reducing agent through the battery in contact with the surfaces of oxidized, discharged electrodes; and valve means for sequentially flowing said reducing agent into the battery and when spent from the battery, for removing electrolyte from and for refilling the battery with electrolyte.
Claim 2
Independent Claim
100 words
A system for recharging a metal-oxidant gas battery having an electrolyte inlet and an electrolyte outlet comprising: a fluid circuit for connection to said inlet and outlet containing: electrolyte storage means; reservoir means containing a supply of fluid reducing agent; pump means for flowing the electrolyte into and out of the battery and for flowing the fluid reducing agent through the battery in contact with the surfaces of oxidized, discharged electrodes; and valve means for sequentially flowing said reducing agent into the battery and when spent from the battery, for removing electrolyte from and for refilling the battery with electrolyte.
Claim 3
Dependent Claim
28 words
A system according to claim 1 in which the reducing fluid is an aqueous solution of a reducing agent having a standard reduction potential greater than 0.049 V.
Claim 4
Dependent Claim
22 words
A system according to claim 2 in which the reducing agent is selected from formaldehyde, monohydrogen phosphite, a hypophosphite, or a dithonite.
Claim 5
Dependent Claim
13 words
A system according to claim 3 in which the reducing agent is formaldehyde.
Claim 6
Dependent Claim
14 words
A system according to claim 1 in which the battery is an iron-air battery.
Claim 7
Dependent Claim
12 words
A system according to claim 1 in which the metal is iron.
Claim 8
Dependent Claim
13 words
A system according to claim 6 in which the oxidant gas is air.
Claim 9
Dependent Claim
17 words
A system according to claim 1 in which the circuit further includes a source of rinsing liquid.
Claim 10
Dependent Claim
22 words
A system according to claim 1 in which the valve means selectively connects the electrolyte outlet to the fluid reducing agent reservoir.
Claim 11
Dependent Claim
31 words
A system according to claim 9 in which the reservoir further includes a drain for removing spent agent and means for filling the reservoir with a charge of fresh reducing agent.
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) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |