USE OF N-ETHYL PYRROLIDONE IN THE PRODUCTION OF ELECTRODES FOR DOUBLE-LAYER CAPACITORS

• US 20130034738A1
• Filed: 11/16/2010
• Published: 02/07/2013
• Est. Priority Date: 12/16/2009
• Status: Abandoned Application

• Current Assignee: Evonik Litarion GmbH (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Evonik Litarion GmbH (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Pilgram, Peter, Modlinger, Armin
• Application Number:
  US13/515,873
• Publication Number:
  US 20130034738A1
• Time in Patent Office: Days
• US Class Current: 428/421
• CPC Class Codes: H01G 11/24 characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor
• CPC Class Codes: H01G 11/28 arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01G 11/70 characterised by their structure
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers

Abstract

The invention relates to the use of N-ethyl pyrrolidone in the production of electrodes for double-layer capacitors.

Claims

1-15. -15. (canceled)

16. A process for coating an aluminum-containing carrier in the course of production of an electrode of a double-layer capacitor, comprising the steps of:

a) providing a composition comprising at least one solvent and/or dispersion medium and additionally at least one polymeric binder,

b) coating the carrier with the composition,

characterized in that

the solvent and/or dispersion medium is or comprises N-ethylpyrrolidone.

17. The process as claimed in claim 16, wherein the polymeric binder is selected from the group comprising polyvinylidene fluoride homopolymers (PVDF);

polyvinylidene fluoride copolymers (PVDF copolymers);

mixtures of PVDF and PVDF copolymer(s);

polytetrafluoroethylene (PTFE);

polyvinyl chloride (PVC);

polyvinyl fluoride (PVF);

polychlorotrifluoroethylene (PCTFE);

polychlorotrifluoroethylene-ethylene (ECTFE);

polytetrafluoroethylene-ethylene (ETFE);

polytetrafluoroethylene-hexafluoropropene (FEP);

polymethyl methacrylate (PMMA);

polyethylene oxide (PEO);

polypropylene oxide (PPO);

polypropylene (PP);

polyethylene (PE);

polyimide (PI); and

styrene-butadiene rubber (SBR).

18. The process as claimed in claim 16, wherein the polymeric binder is selected from the group comprising polyvinylidene fluoride homopolymers (PVDF);

PVDF-hexafluoropropene (PVDF-HFP);

PVDF-tetrafluoroethylene (PVDF-TFE);

PVDF-chlorotetrafluoroethylene (PVDF-CTFE);

mixtures of PVDF and PVDF copolymer(s);

polytetrafluoroethylene (PTFE);

polyvinyl chloride (PVC);

polyvinyl fluoride (PVF);

polychlorotrifluoroethylene (PCTFE);

polychlorotrifluoroethylene-ethylene (ECTFE);

polytetrafluoroethylene-ethylene (ETFE);

polytetrafluoroethylene-hexafluoropropene (FEP);

polymethyl methacrylate (PMMA);

polyethylene oxide (PEO);

polypropylene oxide (PPO);

polypropylene (PP);

polyethylene (PE);

polyimide (PI); and

styrene-butadiene rubber (SBR).

19. The process as claimed in claim 16, wherein the composition is a dispersion and additionally comprises an active material which enables the capture and deposition of electrically charged particles and which is selected from the group comprising graphite, amorphous carbons, activated carbon or mixtures thereof.

20. The process as claimed in claim 19, wherein the specific surface area of the active material is between 1000 and 2000 m²/g.

21. The process as claimed in claim 19, wherein the active material has a mean pore diameter of from 2 to 5 nm.

22. The process as claimed in claim 16, wherein the composition additionally comprises at least one conductivity additive which is selected from the group consisting of fine graphite with d50 between 1 μ

m and 8 μ

m;

carbon blacks with primary particles between 10 and 80 nm;

carbon fibers; and

mixtures thereof.

23. The process as claimed in claim 16, wherein the carrier is an aluminum foil, a laminate comprising aluminum foil, an expanded aluminum metal, an aluminum-coated polymeric foil, or an aluminum-coated sheetlike textile structure.

24. The process as claimed in claim 16, wherein the carrier is an aluminum foil, a laminate comprising aluminum foil, an expanded aluminum metal, an aluminum-coated polymeric foil, or an aluminum-coated sheetlike nonwoven textile structure.

25. The process as claimed in claim 23, wherein the carrier is porous or regularly perforated.

26. The process as claimed in claim 16, wherein the composition comprises an N-ethylpyrrolidone content of 30 to 80% by weight, and an active material content of 20 to 70% by weight, and/or a conductivity additive content of 0 to 5% by weight, based in each case on the composition.

27. The process as claimed in claim 16, wherein the composition comprises an N-ethylpyrrolidone content of 30 to 80% by weight, and a polymeric binder content of 0.5 to 8% by weight, and/or an active material content of 20 to 70% by weight, and/or a conductivity additive content of 0 to 5% by weight, based in each case on the composition.

28. The process as claimed in claim 16, wherein the composition has a viscosity in the range from 1000 to 7000 mPas at a shear rate of 112 s⁻

1, measured at 20°

C.

29. A coated carrier produced by the process according to claim 16.

30. A double-layer capacitor having at least one electrode, which is produced by the process as claimed in claim 16.

31. A composition comprising

at least one solvent and/or dispersion medium,

at least one polymeric binder,

an active material which enables the capture and deposition of electrically charged particles, and

optionally at least one conductivity additive,

wherein the solvent and/or dispersion medium is N-ethylpyrrolidone.

32. The composition as claimed in claim 31, wherein the active material is an activated carbon.

33. The composition as claimed in claim 31, wherein the N-ethylpyrrolidone content is from 30 to 80% by weight, the polymeric binder content is from 0.5 to 8% by weight, the active material content is from 20 to 70% by weight, and any conductivity additive content is from 0 to 5% by weight, based in each case on the composition.

34. A process for production of electrodes for double-layer capacitors which comprises utilizing N-ethylpyrrolidone.