US4158720A
Expired / Lapsed
US
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Lithium-aluminum-iron electrode composition
Assignee: United States Department of Energy
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Filing: 1977-12-28
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Granted: 1979-06-19
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Expires: 1997-12-28
Abstract
Abstract A negative electrode composition is presented for use in a secondary electrochemical cell. The cell also includes an electrolyte with lithium ions such as a molten salt of alkali metal halides or alkaline earth metal halides that can be used in high-temperature cells. The cell's positive electrode contains a a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent in an alloy of aluminum-iron. Various binary and ternary intermetallic phases of lithium, aluminum and iron are formed. The lithium within the intermetallic phase of Al 5 Fe 2 exhibits increased activity over that of lithium within a lithium-aluminum alloy to provide an increased cell potential of up to about 0.25 volt.
Inventors
- 👤 Thomas D. Kaun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:26
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/02; H01M4/36; H01M4/38; H01M4/40; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/1216
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
72 words
A solid electrode composition for use in the negative electrode of a secondary electrochemical cell, said cell also including an electrolyte containing lithium ions, and a positive electrode including a chalcogen or a transition metal chalcogenide, said solid electrode composition comprising about 5 to 50 atom percent lithium and 95 to 50 atom percent alloy of aluminum and iron, said aluminum and iron alloy comprising about 20 to 35 atom percent iron.
Claim 2
Dependent Claim
72 words
A solid electrode composition for use in the negative electrode of a secondary electrochemical cell, said cell also including an electrolyte containing lithium ions, and a positive electrode including a chalcogen or a transition metal chalcogenide, said solid electrode composition comprising about 5 to 50 atom percent lithium and 95 to 50 atom percent alloy of aluminum and iron, said aluminum and iron alloy comprising about 20 to 35 atom percent iron.
Claim 3
Dependent Claim
19 words
The electrode composition of claim 1 wherein said aluminum-iron alloy includes the intermetallic compound Fe 2 Al 5 .
Claim 4
Dependent Claim
22 words
The electrode composition of claim 1 wherein aluminum is included at about 2 to 3 atom parts to each atom part iron.
Claim 5
Dependent Claim
28 words
The electrode composition of claim 1 wherein said electrode comprises a major proportion of Fe 2 Al 5 and minor amounts of FeAl 2 or FeAl 3 .
Claim 6
Dependent Claim
20 words
The electrode composition of claim 1 wherein aluminum and iron are present in about 5 to 12 atom proportions respectively.
Claim 7
Independent Claim
61 words
A method of preparing a negative electrode composition for use in a high-temperature, secondary electrochemical cell including an electrolyte containing lithium ions and a positive electrode including chalcogens or transition metal chalcogenides, said method comprising forming an alloy of aluminum-iron having about 20 to 35 atom percent iron and depositing about 5 to 50 atom percent lithium into the aluminum-iron alloy.
Claim 8
Independent Claim
61 words
A method of preparing a negative electrode composition for use in a high-temperature, secondary electrochemical cell including an electrolyte containing lithium ions and a positive electrode including chalcogens or transition metal chalcogenides, said method comprising forming an alloy of aluminum-iron having about 20 to 35 atom percent iron and depositing about 5 to 50 atom percent lithium into the aluminum-iron alloy.
Claim 9
Dependent Claim
20 words
The method of claim 6 wherein said aluminum-iron alloy is formed into a porous mass prior to depositing lithium therein.
Claim 10
Dependent Claim
65 words
The method of claim 6 further comprising forming a melt of aluminum and iron by heating to a temperature above the melting point of aluminum but below the melting point of iron, solidifying the melt to form a solid aluminum-iron alloy, comminuting the alloy to particles, integrating the particles of alloy into a porous, electrically conductive structure and electrochemically depositing lithium into the aluminum-iron alloy.
Claim 11
Dependent Claim
28 words
The method of claim 8 wherein the particles of aluminum-iron alloy are compacted with electrolyte to form a porous, electrically conductive mass prior to electrochemically depositing lithium therein.
Claim 12
Dependent Claim
19 words
The method of claim 8 wherein the particles of aluminum-iron alloy are distributed into a porous, electrically conductive structure.
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) | 1982-06-18 | 1982-12-18 | 1983-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-18 | 1986-12-18 | 1987-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-18 | 1990-12-18 | 1991-06-19 | $7700.00 | Window Closed / Lapsed |