US5496664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing a positive electrode for lithium secondary batteries
Assignee: VARTA Microbattery GmbH
•
Filing: 1994-08-09
•
Granted: 1996-03-05
•
Expires: 2014-08-09
Abstract
Abstract An active material for a positive electrode for lithium secondary batteries and composed of a lithium-manganese oxide (Li x Mn 2 O 4 ) with a spinel structure is produced by mixing manganese dioxide with lithium formate (HCOOLi) and/or lithium acetate (CH 3 COOLi), heating the resulting mixture for 10 to 100 hours, preferably at a temperature of from 600° C. to 750° C., and if necessary, grinding the heated mixture. The constituents of the mixture contain manganese and lithium in a molar ratio (Mn:Li) of 2:x, where 0.5<x<1.5. The resulting product has an extremely fine crystallinity and exhibits good cycling stability.
Inventors
- 👤 Gerhard Sterr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:49
CPC Classifications
C; C01; C01G; C01G45/00; C01G45/12; C01G45/1221; C01G45/1242; H; H01; H01M; H01M4/00; H01M4/02; H01M4/36; H01M4/48; H01M4/50; H01M4/505; C01P; C01P2002/00; C01P2002/30; C01P2002/32; C01P2006/00; C01P2006/40; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
99 words
A process for producing an active material for a positive electrode for lithium secondary batteries, wherein the active material is composed of a lithium-manganese oxide having a spinel structure, and comprising the steps of: mixing manganese dioxide with a lithium salt selected from the group consisting of lithium formate, lithium acetate, and combinations thereof, thereby producing a mixture; and heating the mixture at a temperature of from 600° C. to 750° C. for between 10 and 100 hours; wherein the mixture is produced by spray-drying a suspension of the manganese dioxide in an aqueous solution of the lithium salt.
Claim 2
Dependent Claim
99 words
A process for producing an active material for a positive electrode for lithium secondary batteries, wherein the active material is composed of a lithium-manganese oxide having a spinel structure, and comprising the steps of: mixing manganese dioxide with a lithium salt selected from the group consisting of lithium formate, lithium acetate, and combinations thereof, thereby producing a mixture; and heating the mixture at a temperature of from 600° C. to 750° C. for between 10 and 100 hours; wherein the mixture is produced by spray-drying a suspension of the manganese dioxide in an aqueous solution of the lithium salt.
Claim 3
Dependent Claim
15 words
The process of claim 1 which further includes the step of grinding the heated mixture.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein the manganese dioxide is a chemically produced product (CMD) or a β-MnO 2 (pyrolusite).
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein the manganese dioxide is mixed with both lithium formate and lithium acetate.
Claim 6
Dependent Claim
24 words
The process of claim 1 wherein the mixture contains manganese and lithium in a molar ratio of manganese to lithium of 2:x, where 0.5<x<1.5.
Claim 7
Dependent Claim
7 words
The process of claim 5 where 0.9<x<1.2.
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) | 1999-03-05 | 1999-09-04 | 2000-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-03-05 | 2003-09-04 | 2004-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-03-05 | 2007-09-04 | 2008-03-05 | $7700.00 | Window Closed / Lapsed |