Patent US3907589A successfully refreshed from Google Patents.
US3907589A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cathode for a secondary electrochemical cell
Assignee: United States Department of Energy
•
Filing: 1974-01-18
•
Granted: 1975-09-23
•
Expires: 1994-01-18
Abstract
Abstract An electrochemical cell is disclosed which comprises an alkali metal anode, a molten salt electrolyte including that alkali metal in ionic form, and an improved cathode. The cathode composition comprises a transition metal sulfide such as FeS2, a particulate current collector, e.g. carbon black, electrolyte and a sulfide product, e.g. Li2S, of the cell reaction in excess of that produced by electrochemical reaction of the transition metal sulfide with the alkali metal in the discharge of the cell. Operation of the cell is performed by first electrocharging the cathode in series with the anode to convert the sulfide reaction product into a usable cathode reactant submerged in molten electrolyte.
Inventors
- 👤 Eddie C Gay
- 👤 Fredric J Martino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:18
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/02; H01M4/36; H01M4/58; H01M4/581; H01M10/00; H01M10/36; H01M10/39; H01M10/399; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/5313; Y10T29/53135
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
92 words
IN A SECONDARY ELECTROCHEMICAL CELL INCLUDING AN ALKALI METAL REACTANT IN THE ANODE, A CATHODE COMPOSITION INCLUDING A CHALCOGEN REACTANT IN THE CATHODE AND AN ELECTROLYTE CONTANING IONS OF SAID ALKALI METAL, THE IMPROVEMENT WHEREIN SAID CATHODE COMPOSITION COMORISES: AT LEAST ONE TRANSITION METAL SULFIDE AND A SULFIDE REACTION PRODUCT OF SAID ALKALI METAL AND SAID TRANSITION METAL SUFIDE, THE TOTAL ATOMIC CONCENTRATION OF SULFUR COMBINED WITH SAID TRANSITION METAL AND SAID ALKALI METAL REACTANT WITHIN SAID CATHODE BEING IN IN STOICHIOMETRIC EXCESS OF THE TOTAL ATOMIC CONCENTRATION OF SAID TRANSISTION METAL.
Claim 2
Dependent Claim
92 words
IN A SECONDARY ELECTROCHEMICAL CELL INCLUDING AN ALKALI METAL REACTANT IN THE ANODE, A CATHODE COMPOSITION INCLUDING A CHALCOGEN REACTANT IN THE CATHODE AND AN ELECTROLYTE CONTANING IONS OF SAID ALKALI METAL, THE IMPROVEMENT WHEREIN SAID CATHODE COMPOSITION COMORISES: AT LEAST ONE TRANSITION METAL SULFIDE AND A SULFIDE REACTION PRODUCT OF SAID ALKALI METAL AND SAID TRANSITION METAL SUFIDE, THE TOTAL ATOMIC CONCENTRATION OF SULFUR COMBINED WITH SAID TRANSITION METAL AND SAID ALKALI METAL REACTANT WITHIN SAID CATHODE BEING IN IN STOICHIOMETRIC EXCESS OF THE TOTAL ATOMIC CONCENTRATION OF SAID TRANSISTION METAL.
Claim 3
Dependent Claim
15 words
The improved cathode composition of claim 1 comprising FeS2 and at least 2 w/o Li2S.
Claim 4
Dependent Claim
28 words
The improved cathode composition of claim 2 wherein the total atomic concentration of sulfur is in excess of twice the total atomic concentration of iron in said cathode.
Claim 5
Dependent Claim
43 words
The improved cathode composition of claim 3 wherein the atomic concentration of sulfur is about four times the atomic concentration of iron and the atom equivalents of sulfur in said cathode are about twice that required to combine with iron as iron disulfide.
Claim 6
Dependent Claim
23 words
The electrochemical cell of claim 4 wherein said cathode comprises by weight about 33% FeS2, 27%, Li2S, 33% electrolyte and 7% carbon black.
Claim 7
Independent Claim
101 words
A METHOD OF PREPARING A CATHODE FOR USE IN A SECONDARY ELECTROCHEMICAL CELL WHERREIN SAID CELL INCLUDES A CATHODE STRUCTURE WITH INNER CHAMBER, AN ANODE WITH AN ALKALI METAL REACTANT, AND AN ELECTROLYTE INCLUDING IONS OF SAID ALKALI METAL IN CONTACT WITH BOTH OF SAID ELECTRODES, THE IMPROVEMENT COMPRISING: A. BLEDING PARTICULATE TRANSITION METAL SULFIDE, SULFIDE REACTION PRODUCT OF SAID ANODE REACTANT AND SAID TRANSITION METAL SULFIE, MOLTEN ELECTROLYTE AND PARTICLES OF ELECTRICALLY CONDUCTIVE MATERIAL TO FORM ACATHODE COMPOSITION: AND B. ASSEMBLING SAID CATHODE COMPOSITION INTO SAID CATHODE STRUCTURE OF SAID ELECTROCHEMICAL CELL FOR USE AS A SOURCE OF ELECTRICAL POWDER.
Claim 8
Independent Claim
101 words
A METHOD OF PREPARING A CATHODE FOR USE IN A SECONDARY ELECTROCHEMICAL CELL WHERREIN SAID CELL INCLUDES A CATHODE STRUCTURE WITH INNER CHAMBER, AN ANODE WITH AN ALKALI METAL REACTANT, AND AN ELECTROLYTE INCLUDING IONS OF SAID ALKALI METAL IN CONTACT WITH BOTH OF SAID ELECTRODES, THE IMPROVEMENT COMPRISING: A. BLEDING PARTICULATE TRANSITION METAL SULFIDE, SULFIDE REACTION PRODUCT OF SAID ANODE REACTANT AND SAID TRANSITION METAL SULFIE, MOLTEN ELECTROLYTE AND PARTICLES OF ELECTRICALLY CONDUCTIVE MATERIAL TO FORM ACATHODE COMPOSITION: AND B. ASSEMBLING SAID CATHODE COMPOSITION INTO SAID CATHODE STRUCTURE OF SAID ELECTROCHEMICAL CELL FOR USE AS A SOURCE OF ELECTRICAL POWDER.
Claim 9
Dependent Claim
47 words
The method of claim 6 wherein said electrochemical cell is heated to an operating temperature at which said cathode composition is submerged in molten electrolyte; and electrically charged to convert said sulfide reaction product into cathode reactant other than said transition metal sulfide at said operating temperature.
Claim 10
Dependent Claim
63 words
The method according to claim 7 wherein said sulfide reaction product is Li2S, said transition metal sulfide is FeS2 and said electrolyte comprises a eutectic composition of LiF-LiCl-KCl having a melting point of about 350*C., said Li2S is included within said cathode composition in an amount to provide a stoichiometric excess of sulfide within said cathode to that needed to combine as FeS2.
Claim 11
Dependent Claim
43 words
The method according to claim 7 wherein said cathode composition is formed by blending powders of lithium sulfide and iron disulfide with molten LiF-LiCl-KCl electrolyte in a weight proportion of about 27%, 33% and 33%, respectively, along with about 7 w/o carbon black.
Claim 12
Dependent Claim
32 words
The method of claim 7 wherein said cathode composition is assembled in said cell within a cathode enclosure having a window of porous fabric facing said anode and exposed to said electrolyte.
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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |