Method for making electrode

• US 6,589,299 B2
• Filed: 02/13/2001
• Issued: 07/08/2003
• Est. Priority Date: 02/13/2001
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Graham, Katherine A., Eastin, Brian C., Hollobaugh, Tony B., Missling, Jeffrey J.
• Primary Examiner(s): CHANEY, CAROL DIANE
• Application Number:
  US09/782,748
• Publication Number:
  US 20020136948A1
• Time in Patent Office: 875 Days
• Field of Search: 296/235, 429/300, 429/218.1, 429/127, 429/162
• US Class Current: 29/623.5
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0411 by extrusion
• CPC Class Codes: H01M 4/0483 by methods including the handling of a melt H01M4/0438, take precedence
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

Described are methods of making electrodes for electrochemical systems, especially cathodes for lithium polymer batteries, and products prepared from the methods; the methods involve the use of a reciprocating extruder, the extrusion of essentially solvent-free systems, or both.

Claims

1. A method for combining electrode components comprising:

an active material,

an ionically-conductive polymer,

an electrolyte salt,

and no added solvent,

the method comprising processing the electrode components using a reciprocating single screw extruder.

2. The method of claim 1 wherein each electrode component contains essentially no solvent.

3. The method of claim 1 wherein each electrode component is a dry material that contains no solvent.

4. The method of claim 1 wherein the combined electrode components include essentially no solvent.

5. The method of claim 1 wherein the combined electrode components include a total of less than 0.5 percent by weight solvent.

6. The method of claim 1 wherein the active material comprises a metal oxide.

7. The method of claim 1 wherein the active material comprises a metal oxide selected from the group consisting of oxides of vanadium, manganese, cobalt, nickel, chromium, aluminum, tungsten, molybdenum, titanium, their lithiated versions, and mixtures thereof.

8. The method of claim 1 where the active material comprises a vanadium oxide.

9. The method of claim 1 wherein the electrode components comprise from about 50-86 weight percent active material.

10. The method of claim 1 wherein the electrode components comprise from about 60-68 weight percent active material.

11. The method of claim 1 wherein the components further comprise electrically-conductive material comprising carbon black, graphite, or a combination thereof.

12. The method of claim 1 wherein the ionically-conductive polymer comprises a derivative of monomers comprising an oxygen-containing monomer or a nitrogen-containing monomer.

13. The method of claim 1 wherein the ionically-conductive polymer comprises a polyalkylene oxide polymer or copolymer.

14. The method of claim 1 wherein the electrolyte salt comprises a fluorinated lithium salt.

15. The method of claim 1 wherein the electrolyte salt is chosen from the group consisting of lithium hexafluoroarsenate, lithium perchlorate, lithium hexafluorophosphate, lithium trifluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(perfluoroethanesulfonyl)imide, lithium tris(trifluoromethanesulfonyl)methide, and mixtures thereof.

16. The method of claim 1 wherein the electrode components comprise:

greater than about 50 weight percent active material,

from about 1 to about 10 weight percent electrically-conductive material comprising carbon black, graphite, or a combination thereof,

from about 10 to about 40 weight percent ionically-conductive polymer,

from about 3 to about 15 weight percent lithium salt,

and less than about 0.5 weight percent solvent.

17. The method of claim 16 wherein the active material comprises a metal oxide selected from the group consisting of oxides of vanadium, manganese, cobalt, nickel, chromium, aluminum, tungsten, molybdenum, titanium, their lithiated versions and mixtures thereof.

18. The method of claim 16 where the ionically-conductive polymer comprises a derivative of monomers comprising an oxygen-containing monomer or a nitrogen-containing monomer.

19. The method of claim 16 wherein the ionically-conductive polymer comprises a polyalkylenoxide polymer or copolymer.

20. The method of claim 16 wherein the lithium salt is chosen from the group consisting of lithium hexafluoroarsenate, lithium perchlorate, lithium hexafluorophosphate, lithium trifluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(perfluoroethanesulfonyl)imide, lithium tris(trifluoromethanesulfonyl)methide, and mixtures thereof.

21. The method of claim 1 wherein the extruder comprises multiple feed inlets and a downstream extruding end, and wherein

the ionic salt feeds into the extruder at a first feed position,

the ionically-conductive polymer, the active material, and the electrically-conductive material each feed into the extruder at one or more feed positions downstream from the ionic salt feed position.

22. The method of claim 21 wherein the ionically-conductive polymer feeds into the extruder as a solid containing no solvent.

23. The method of claim 21 wherein the ionically-conductive polymer feeds into the extruder as a melt.

24. The method of claim 21 wherein the ionically-conductive polymer feeds into the extruder at a second position downstream from the first feed position, and a mixture comprising active material and electrically-conductive material is fed at a third feed position downstream from the second feed position.

25. The method of claim 21 wherein ionically-conductive polymer, active material, and electrically-conductive material are combined and fed into the extruder as a single mixture at a second feed position.

26. The method of claim 21 wherein a mixture comprising active material, electrically-conductive material, and ionically-conductive polymer is fed at a second feed position, and a mixture comprising active material and electrically-conductive material is fed at a third feed position downstream from the second feed position.

27. A method for combining electrode components comprising:

an active material,

an ionically-conductive polymer,

an electrolyte salt,

wherein the method comprises processing the electrode components using a reciprocating single screw extruder and

wherein an ionically-conductive polymer salt complex material is processed in a molten state.

28. A method of producing a battery cathode, the method comprising processing a mixture of ingredients comprising:

greater than about 50 weight percent active material,

from about 1 to about 10 weight percent electrically-conductive material comprising carbon black, graphite, or a combination thereof,

from about 10 to about 40 weight percent polymer comprising ionically-conductive polyalkylenoxide polymer,

from about 3 to about 15 weight percent fluorinated lithium salt, wherein the mixture includes a total of less than about 0.5 percent by weight solvent, the method comprising using a reciprocating extruder and processing an ionically-conductive polymer salt complex in a molten state.

29. The method of claim 28 further comprising depositing an extrudate of the electrode components onto a substrate.

30. The method of claim 29 wherein the substrate is chosen from the group consisting of a liner, a current collector, a separator, or an electrolyte.

31. The method of claim 28 wherein the ingredients include at least about 50 weight percent active ingredient.

32. The method of claim 28 wherein the ingredients include at least about 60 weight percent lithiated vanadium oxide.

33. A method for combining electrode components comprising:

ionically-conductive polymer, electrolyte salt,

the method comprising processing electrolyte components using a reciprocating single screw extruder,

wherein ionically-conductive polymer is fed to the extruder downstream from electrolyte salt.

34. The method of claim 33 wherein the ionically-conductive polymer feeds into the extruder as a melt.

35. The method of claim 33 wherein the electrode components contain no added solvent.

36. The method of claim 33 wherein the components further comprise active material.