US4959282A
Expired / Lapsed
US
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Cathode active materials, methods of making same and electrochemical cells incorporating the same
Assignee: Moli Energy Ltd
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Filing: 1988-07-11
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Granted: 1990-09-25
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Expires: 2008-07-11
Abstract
Abstract Cathode-active material for electrochemial cells is prepared by reacting gamma phase MnO 2 with Li. The molar ratio of Li to MnO 2 is about 0.33 to about 0.43.
Inventors
- 👤 Jeffery R. Dahn
- 👤 Brian M. Way
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:06
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/02; H01M4/36; H01M4/48; H01M4/50; H01M4/505; C; C01; C01G; C01G45/00; C01G45/02; C01G45/024; C01G45/12; C01G45/1221; C01G45/1228; H01M4/13; H01M4/131; H01M4/139; H01M4/1391; H01M4/485; C01P; C01P2002/00; C01P2002/50; C01P2002/52; C01P2002/54; C01P2002/70; C01P2002/74; C01P2006/00; C01P2006/40; H01M10/00; H01M10/05; H01M10/052; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
58 words
A method of making a cathode active material for an electrochemical cell comprising the steps of providing a substantially dry intermediate including a lithium-containing compound and gamma MnO 2 at a mean molar ratio of lithium to gamma MnO 2 of about 0.33 to about 0.43 and heat-treating said intermediate in a drying atmosphere above about 300° C.
Claim 2
Independent Claim
58 words
A method of making a cathode active material for an electrochemical cell comprising the steps of providing a substantially dry intermediate including a lithium-containing compound and gamma MnO 2 at a mean molar ratio of lithium to gamma MnO 2 of about 0.33 to about 0.43 and heat-treating said intermediate in a drying atmosphere above about 300° C.
Claim 3
Dependent Claim
22 words
A method as claimed in claim 1 wherein said gamma MnO 2 in said intermediate is porous MnO 2 in particulate form.
Claim 4
Dependent Claim
28 words
A method as claimed in claim 2 wherein said heat-treating step is conducted at between about 300° C. and about 450° C. for at least about 30 minutes.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 3 wherein said heat-treating step is conducted at about 355° to about 385° C. for at least about one hour.
Claim 6
Dependent Claim
49 words
A method as claimed in claim 2 wherein said step of providing said intermediate includes the steps of contacting said particulate MnO 2 with a solution of said lithium-containing compound in a solvent and evaporating said solvent from said particulate MnO 2 while agitating said particulate MnO 2 .
Claim 7
Dependent Claim
30 words
A method as claimed in claim 5 wherein said said evaporation and agitation steps are continued at least until said particulate MnO 2 is substantially devoid of free liquid solvent.
Claim 8
Dependent Claim
25 words
A method as claimed in claim 6 wherein the dry intermediate material resulting from said evaporation step is transferred directly to said heat treating step.
Claim 9
Dependent Claim
14 words
A method as claimed in claim 6 wherein said solvent consists essentially of water.
Claim 10
Dependent Claim
26 words
A method as claimed in claim 8 wherein said lithium-containing compound is selected from the group consisting of LiOH, Li 2 O and LiNO 3 .
Claim 11
Dependent Claim
15 words
A method as claimed in claim 9 wherein said lithium-containing compound consists essentially of LiOH.
Claim 12
Dependent Claim
30 words
A method as claimed in claim 2 wherein said providing step is conducted so that the mean molar ratio of Li to MnO 2 is about 0.36 to about 0.40.
Claim 13
Dependent Claim
12 words
A cathode-active material made by a process as claimed in claim 1.
Claim 14
Dependent Claim
12 words
A cathode-active material made by a process as claimed in claim 6.
Claim 15
Dependent Claim
12 words
A cathode-active material made by a process as claimed in claim 10.
Claim 16
Dependent Claim
18 words
An electrochemical cell comprising a lithium-containing anode, an electrolyte and a cathode-active material as claimed in claim 12.
Claim 17
Dependent Claim
48 words
A cathode-active material made by a process as claimed in claim 1 having a stoichiometric formula Li y MnO 2 , wherein y is about 0.33 to about 0.43, at least a portion of said material being X-phase, the material having R 53/37 of at least about 0.6.
Claim 18
Dependent Claim
15 words
A cathode-active material according to claim 16 having R 53/37 of at least about 0.7.
Claim 19
Dependent Claim
13 words
A cathode-active material according to claim having R 45/37 less than about 0.15.
Claim 20
Dependent Claim
18 words
An electrochemical cell comprising a lithium anode, an electrolyte and a cathode-active material as claimed in claim 16.
References Cited (Backward Citations)
DE2058910A1
Cited
US4312930A
Cited
US4399202A
Cited
US4379817A
Cited
JPS5931182A
Cited
US4465747A
Cited
JPS6116473A
Cited
JPS6220250A
Cited
JPS62108455A
Cited
JPS62126556A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |