Patent US4264689A successfully refreshed from Google Patents.
US4264689A
Expired / Lapsed
US
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Additive for electrochemical cell stability
Assignee: Duracell Inc USA
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Filing: 1979-10-01
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Granted: 1981-04-28
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Expires: 1999-10-01
Abstract
Abstract A nonaqueous electrochemical cell and a method for the construction thereof wherein the cell contains a metal salt additive such as lithium nitrate (LiNO 3 ) or calcium nitrate Ca(NO 3 ) 2 which reduces the reactivity of substantially the entire active cathode surface. Electrolyte solvents such as propylene carbonate are thereby substantially prevented from reacting, on the surface of the cathode, with oxidizing agents within the cell. Decomposition of the electrolyte solvent with gaseous evolution is substantially reduced and cell stability is enhanced. The metal salt additives are particularly useful in nonaqueous cells containing manganese dioxide cathodes.
Inventors
- 👤 Peter R. Moses
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:14
CPC Classifications
H; H01; H01M; H01M6/00; H01M6/14; H01M6/16; H01M4/00; H01M4/02; H01M4/06; H01M4/36; H01M4/48; H01M4/483; H01M4/50; H01M4/502; H01M6/162; H01M6/168; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49108
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
53 words
A method of stabilizing a nonaqueous electrochemical cell comprising an active metal anode, a cathode having active surface functional groups, and a nonaqueous electrolyte solvent having an electrolyte salt dissolved therein, said method comprising the step of partially deactivating substantially all of the active surface of said cathode prior to initial cell discharge.
Claim 2
Independent Claim
53 words
A method of stabilizing a nonaqueous electrochemical cell comprising an active metal anode, a cathode having active surface functional groups, and a nonaqueous electrolyte solvent having an electrolyte salt dissolved therein, said method comprising the step of partially deactivating substantially all of the active surface of said cathode prior to initial cell discharge.
Claim 3
Dependent Claim
41 words
The method of claim 1 wherein said method comprises the step of including a metal salt within said cathode which reacts with said active surface functional groups on said cathode to alter them to less active states to provide said deactivation.
Claim 4
Dependent Claim
36 words
The method of claim 1 wherein said method comprises the step of including a metal salt within said cell which reacts with said cathode to partially discharge said cathode at its surface to provide said deactivation.
Claim 5
Dependent Claim
24 words
The method of claim 2 or 3 wherein said metal salt is present in said cathode in amounts up to 5% by weight thereof.
Claim 6
Dependent Claim
62 words
The method of claim 1 wherein said cathode is made by the steps comprised of mixing a cathode active material with a metal salt which reacts with and deactivates the surface functional groups of said cathode active material, heating said metal salt to initiate said reaction thereby providing said deactivation of the active surface of said cathode and thereafter forming said cathode.
Claim 7
Dependent Claim
31 words
The method of claim 5 wherein said cathode active material comprises electrolytic gamma-manganese dioxide and wherein said gamma-manganese dioxide is converted to beta-MnO 2 during said heating of said metal salt.
Claim 8
Dependent Claim
24 words
The method of claim 6 wherein said metal salt is selected from the group consisting of alkali and alkaline earth metal nitrates and nitrites.
Claim 9
Dependent Claim
20 words
The method of claim 7 wherein said metal salt is selected from the group consisting of lithium and calcium nitrate.
Claim 10
Dependent Claim
12 words
The method of claim 8 wherein said metal salt is lithium nitrate.
Claim 11
Dependent Claim
18 words
The method of claim 6 wherein said nonaqueous electrolyte solvent is subject to oxidation decomposition and gaseous evolution.
Claim 12
Dependent Claim
12 words
The method of claim 10 wherein said electrolyte solvent comprises propylene carbonate.
Claim 13
Dependent Claim
11 words
A cell made in accordance with the method of claim 1.
Claim 14
Dependent Claim
17 words
The cell of claim 12 wherein said cell comprises a lithium anode, and a beta-MnO 2 cathode.
Claim 15
Dependent Claim
17 words
The cell of claim 13 wherein said cell further includes an electrolyte solvent comprised of propylene carbonate.
Claim 16
Dependent Claim
15 words
The cell of claim 14 wherein said cell further includes a lithium perchlorate electrolyte salt.
Claim 17
Independent Claim
67 words
A method for making a cathode for a nonaqueous electrochemical cell comprising the steps of mixing a cathode active material having active surface functional groups with a metal salt which reacts with and deactivates said surface functional groups of said cathode active material, heating said metal salt to initiate said reaction thereby providing said deactivation of the active surface of said cathode and thereafter forming said cathode.
Claim 18
Independent Claim
67 words
A method for making a cathode for a nonaqueous electrochemical cell comprising the steps of mixing a cathode active material having active surface functional groups with a metal salt which reacts with and deactivates said surface functional groups of said cathode active material, heating said metal salt to initiate said reaction thereby providing said deactivation of the active surface of said cathode and thereafter forming said cathode.
Claim 19
Dependent Claim
31 words
The method of claim 16 wherein said cathode active material comprises electrolytic gamma-manganese dioxide and wherein said gamma-manganese dioxide is converted to beta-MnO 2 during said heating of said metal salt.
Claim 20
Dependent Claim
24 words
The method of claim 17 wherein said metal salt is selected from the group consisting of alkali and alkaline earth metal nitrates and nitrites.
Claim 21
Dependent Claim
20 words
The method of claim 18 wherein said metal salt is selected from the group consisting of lithium and calcium nitrate.
Claim 22
Dependent Claim
12 words
The method of claim 19 wherein said metal salt is lithium nitrate.
Claim 23
Dependent Claim
11 words
A cell having a cathode made in accordance with claim 19.
Claim 24
Dependent Claim
12 words
The cell of claim 21 wherein said cell contains a lithium anode.
Claim 25
Dependent Claim
15 words
A cathode for an electrochemical cell made in accordance with the method of claim 19.
Claim 26
Dependent Claim
11 words
A cell having a cathode made in accordance with claim 17.
Claim 27
Dependent Claim
27 words
The method of claim 4 or 16 wherein said metal salt comprises up to 5% of the mixture of the cathode active material and said metal salt.
Claim 28
Dependent Claim
15 words
A cathode for an electrochemical cell made in accordance with the method of claim 16.
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) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |