US3947291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochemical cell assembled in discharged state
Assignee: Energy Research and Development Administration ERDA
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Filing: 1974-09-30
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Granted: 1976-03-30
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Expires: 1994-09-30
Abstract
Abstract A secondary, electrochemical cell is assembled in a completely discharged state within a sealed containment. As assembled, the cell includes a positive electrode separated from a negative electrode by a molten salt electrolyte. The positive electrode is contained within a porous structure, permitting passage of molten electrolyte, and includes one or more layers of a metallic mesh, e.g. iron, impregnated with an intimate mixture of lithium sulfide and the electrolyte. The negative electrode is a porous plaque of aluminum metal. Prior to using the cell, an electrical charge forms lithium-aluminum alloy within the negative electrode and metal sulfide within the positive electrode.
Inventors
- 👤 Neng-Ping Yao
- 👤 William J. Walsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:31
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/36; H01M10/39; H01M10/399; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
208 words
A completely discharged, secondary electrochemical cell assembly having a cell housing, a positive and a negative electrode disposed within said housing, a molten electrolyte including a lithium salt intermediate said positive and negative electrodes, said cell as assembled comprising: in said positive electrode, a porous containment structure penetrable by said electrolyte in molten state, a metallic mesh comprising a metal selected from the group consisting of Fe, Co, Ni, Cu and Mo disposed in said containment structure, an intimate mixture consisting essentially of solid, particulate Li 2 S and said molten electrolyte embedded into said metallic mesh in uniform quantities throughout said mesh, and a positive electrode terminal in electrical contact with said mixture and said metallic mesh; and in said negative electrode, a porous solid mass consisting essentially of aluminum metal, impregnable by said electrolyte in molten state, and a negative electrode terminal in electrical contact with said porous mass of aluminum, said negative and said positive electrode terminals being electrically accessible from outside said cell housing for connection of a source of electrical potential to electrochemically form a metallic sulfide of a metal selected from the group consisting of Fe, Co, Ni, Cu and Mo within said positive electrode and lithium-aluminum alloy within said negative electrode.
Claim 2
Dependent Claim
208 words
A completely discharged, secondary electrochemical cell assembly having a cell housing, a positive and a negative electrode disposed within said housing, a molten electrolyte including a lithium salt intermediate said positive and negative electrodes, said cell as assembled comprising: in said positive electrode, a porous containment structure penetrable by said electrolyte in molten state, a metallic mesh comprising a metal selected from the group consisting of Fe, Co, Ni, Cu and Mo disposed in said containment structure, an intimate mixture consisting essentially of solid, particulate Li 2 S and said molten electrolyte embedded into said metallic mesh in uniform quantities throughout said mesh, and a positive electrode terminal in electrical contact with said mixture and said metallic mesh; and in said negative electrode, a porous solid mass consisting essentially of aluminum metal, impregnable by said electrolyte in molten state, and a negative electrode terminal in electrical contact with said porous mass of aluminum, said negative and said positive electrode terminals being electrically accessible from outside said cell housing for connection of a source of electrical potential to electrochemically form a metallic sulfide of a metal selected from the group consisting of Fe, Co, Ni, Cu and Mo within said positive electrode and lithium-aluminum alloy within said negative electrode.
Claim 3
Dependent Claim
25 words
The electrochemical cell of claim 1 wherein a plurality of said metallic mesh embedded with said mixture are disposed in layers within said positive electrode.
Claim 4
Dependent Claim
24 words
The electrochemical cell of claim 1 wherein said metallic mesh comprises a transition metal selected from the group consisting of iron, cobalt and nickel.
Claim 5
Dependent Claim
72 words
The electrochemical cell of claim 3 wherein said transition metal is iron included in stoichiometric ratio in respect to said Li 2 S sufficient to form FeS 2 without excess Li 2 S but insufficient to form FeS with excess iron and wherein there is included within said containment structure of said positive electrode a mesh of an inert metal having an oxidation potential versus lithium substantially higher than that of iron.
Claim 6
Dependent Claim
25 words
The electrochemical cell of claim 4 wherein said inert metal is selected from the group consisting of molybdenum, tungsten and alloys of molybdenum and tungsten.
Claim 7
Dependent Claim
42 words
The electrochemical cell of claim 3 wherein said transition metal is iron included in substantial stoichimetric excess in respect to Li 2 S of that required to form FeS, said excess iron being retained in said positive electrode as current collector material.
Claim 8
Dependent Claim
40 words
The electrochemical cell of claim 1 wherein said intimate mixture of Li 2 S and said electrolyte comprises particles of Li 2 S coated with fused electrolyte in a composition by weight of about 60 to 90% Li 2 S.
Claim 9
Dependent Claim
33 words
The electrochemical cell of claim 7 wherein said coated particles are of about 5 microns to 30 microns in size and are in compacted engagement with adjacent particles and with said metallic mesh.
Claim 10
Independent Claim
153 words
A method of preparing an electrochemical cell having a positive electrode with iron sulfide as a reactant, a negative electrode with lithium, in the form of lithium-aluminum alloy, as a reactant, and an electrolyte including a lithium salt intermediate said positive and negative electrodes, the improved method comprising admixing particulate lithium sulfide and said electrolyte to form a uniform and intimate mixture; pressing said intimate mixture into interstices within a metallic mesh of a metal comprising Fe to form a positive electrode compact that is substantially free of iron sulfides; enclosing said compact within a containment structure including an electrical terminal in electrical contact with said compact; sealing said positive electrode compact within said cell housing along with said electrolyte and a negative electrode structure consisting essentially of a porous aluminum mass; and electrochemically charging said sealed cell to form iron sulfide within said positive electrode and lithium-aluminum alloy within said negative electrode.
Claim 11
Independent Claim
153 words
A method of preparing an electrochemical cell having a positive electrode with iron sulfide as a reactant, a negative electrode with lithium, in the form of lithium-aluminum alloy, as a reactant, and an electrolyte including a lithium salt intermediate said positive and negative electrodes, the improved method comprising admixing particulate lithium sulfide and said electrolyte to form a uniform and intimate mixture; pressing said intimate mixture into interstices within a metallic mesh of a metal comprising Fe to form a positive electrode compact that is substantially free of iron sulfides; enclosing said compact within a containment structure including an electrical terminal in electrical contact with said compact; sealing said positive electrode compact within said cell housing along with said electrolyte and a negative electrode structure consisting essentially of a porous aluminum mass; and electrochemically charging said sealed cell to form iron sulfide within said positive electrode and lithium-aluminum alloy within said negative electrode.
Claim 12
Dependent Claim
39 words
The method according to claim 9 wherein said intimate mixture of lithium sulfide and electrolyte is formed by contacting said particulate Li 2 S with molten electrolyte to produce Li 2 S particles having a coating of fused electrolyte.
Claim 13
Dependent Claim
47 words
The method of claim 10 wherein said intimate mixture of lithium sulfide and electrolyte is repetitively ground and heated to a temperature in excess of the melting point of said electrolyte to form lithium sulfide particles coated with electrolyte of sizes between 5 microns and 30 microns.
Claim 14
Dependent Claim
42 words
The method of claim 9 wherein said intimate mixture of lithium sulfide and electrolyte is pressed into a plurality of stacked metallic mesh at a pressure of about 200 to 700 kg/cm 2 for an interval of about 10 to 30 minutes.
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) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |