Composite solid polymer electrolyte membranes

• US 20050031925A1
• Filed: 05/22/2004
• Published: 02/10/2005
• Est. Priority Date: 03/03/1999
• Status: Active Grant

• Current Assignee: Foster-Miller Incorporated (Thermo Fisher Scientific Incorporated)
• Original Assignee: Foster-Miller Incorporated (Thermo Fisher Scientific Incorporated)
• Inventors: Stoler, Emily J., Kovar, Robert F., Ofer, David, Nair, Bindu R.
• Granted Patent: US 7,550,216 B2
• Time in Patent Office: Days
• US Class Current: 429/431
• CPC Class Codes: B01D 2323/30 Cross-linking
• CPC Class Codes: B01D 67/0088 Physical treatment with compounds, e.g. swelling, coating or impregnation
• CPC Class Codes: B01D 67/0093 Chemical modification
• CPC Class Codes: B01D 69/141 Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
• CPC Class Codes: B01D 71/32 containing fluorine atoms
• CPC Class Codes: B01D 71/52 Polyethers
• CPC Class Codes: B01D 71/5222 Polyetherketone, polyetheretherketone, or polyaryletherketone
• CPC Class Codes: B01D 71/56 Polyamides, e.g. polyester-amides
• CPC Class Codes: B01D 71/62 Polycondensates having nitrogen-containing heterocyclic rings in the main chain
• CPC Class Codes: B01D 71/64 Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: B01D 71/643 Polyether-imides
• CPC Class Codes: B01D 71/66 Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
• CPC Class Codes: B01D 71/68 Polysulfones; Polyethersulfones
• CPC Class Codes: B01D 71/82 characterised by the presence of specified groups, e.g. introduced by chemical after-treatment
• CPC Class Codes: C08J 5/2218 Synthetic macromolecular compounds
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 8/0289 Means for holding the electrolyte solid polymer electrolytes H01M8/1018
• CPC Class Codes: H01M 8/1007 with both reactants being gaseous or vaporised H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1009 with one of the reactants being liquid, solid or liquid-charged H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1025 : having only carbon and oxygen, e.g. polyethers, sulfonated polyetheretherketones [S-PEEK], sulfonated polysaccharides, sulfonated celluloses or sulfonated polyesters
• CPC Class Codes: H01M 8/1027 : having carbon, oxygen and other atoms, e.g. sulfonated polyethersulfones [S-PES]
• CPC Class Codes: H01M 8/103 : having nitrogen, e.g. sulfonated polybenzimidazoles [S-PBI], polybenzimidazoles with phosphoric acid, sulfonated polyamides [S-PA] or sulfonated polyphosphazenes [S-PPh]
• CPC Class Codes: H01M 8/1032 : having sulfur, e.g. sulfonated-polyethersulfones [S-PES]
• CPC Class Codes: H01M 8/1039 : halogenated, e.g. sulfonated polyvinylidene fluorides
• CPC Class Codes: H01M 8/106 : characterised by the chemical composition of the porous support
• CPC Class Codes: H01M 8/1067 : characterised by their physical properties, e.g. porosity, ionic conductivity or thickness
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells

Abstract

The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with a water soluble ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

Claims

1. A composite solid polymer electrolyte membrane (SPEM) comprising a porous polymer substrate interpenetrated with an water soluble ion-conducting material, wherein

(i) the porous polymer substrate comprises a homopolymer or copolymer of a liquid crystalline polymer or a solvent soluble thermoset or thermoplastic aromatic polymer, and

(ii) the ion-conducting material comprises a water soluble homopolymer or water soluble copolymer of at least one of a sulfonated, phosphonated or carboxylated ion-conducting aromatic polymer, a partially fluorinated ionomer or a perfluorinated ionomer.

2. The SPEM of claim 1, wherein the ion-conducting aromatic polymer comprises a wholly aromatic ion-conducting polymer.

3. The SPEM of claim 1, wherein the ion-conducting aromatic polymer comprises a sulfonated, phosphonated or carboxylated polyimide polymer.

4. The SPEM of claim 2, wherein the sulfonated wholly-aromatic ion-conducting polymer comprises a sulfonated derivative of at least one of a polysulfone (PSU), polyphenylsulfone (PPSU), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSO2), polyphenylene sulfide sulfone (PPS/SQ), polyparaphenylene (PPP), polyphenylquinoxaline (PPQ), polyarylketone (PK), polyetherketone (PEK), polybenzazole (PBZ) and polyaramid (PAR) polymer.

5. The SPEM of claim 4, wherein

(i) the polysulfone polymer comprises at least one of a polyethersulfone (PES), polyetherethersulfone (PEES), polyarylsulfone, polyarylethersulfone (PAS), polyphenylsulfone (PPSU) and polyphenylenesulfone (PPSO₂) polymer,

(ii) the polybenzazole (PBZ) polymer comprises a polybenzoxaxole (PBO) polymer;

(iii) the polyetherketone (PEK) polymer comprises at least one of a polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone-ketone (PEEKK) and polyetherketoneetherketone-ketone (PEKEKK) polymer; and

(iv) the polyphenylene oxide (PPO) polymer comprises at least one of a 2,6-diphenyl PPO, 2,6-dimethyl PPO and 1,4-poly phenylene oxide polymer.

6. The SPEM of claim 1, wherein the ion-conducting material comprises at least one of a polystyrene sulfonic acid (PSSA), poly(trifluorostyrene) sulfonic acid, polyvinyl phosphonic acid (PVPA), polyacrylic acid and polyvinyl sulfonic acid (PVSA) polymer.

7. The SPEM of claim 1, wherein the porous polymer substrate comprises a homopolymer or copolymer of at least one of a substituted or unsubstituted polybenzazole polymer, and wherein the ion-conducting material comprises a sulfonated derivative of a homopolymer or copolymer of at least one of a polysulfone (PSU), polyphenylene sulfoxide (PPSO) and polyphenylene sulfide sulfone (PPS/SO₂) polymer.

8. The SPEM of claim 7, wherein the polysulfone polymer comprises at least one of a polyethersulfone (PES) and polyphenylsulfone (PPSU) polymer.

9. The SPEM of claim 8, wherein the polysulfone polymer is produced by condensation of (4,4′

-dihalophenyl)sulfone, sulfonated (4,4′

-dihalophenyl)sulfone or a mixture thereof with 4,4′

-bisphenolbiphenol, or 4,4′

-biphenylbiphenyl-dithiol, 1,4-hydroquinone, 1,4-benzene dithiol, and mixtures thereof, each of which may be optionally sulfonated.

10. The SPEM of claim 9, wherein at least 75% of the (4,4′

-dihalophenyl)sulfone monomer is sulfonated at the 3 and 3′

position.

11. The SPEM of claim 9, wherein at least 90% of the (4,4′

-dihalophenyl)sulfone monomer is sulfonated at the 3 and 3′

position.

12. The SPEM of claim 9, wherein substantially all of the (4,4′

-dihalophenyl)sulfone monomer is sulfonated at the 3 and 3′

position.

13. The SPEM of claim 9, wherein the polysulfone polymer is a compound of the formula:

14. The SPEM of claim 13, wherein the polysulfone polymer is a compound of the formula:

15. The SPEM of claim 14, wherein p is an integer of between about 5 and about 500.

16. The SPEM of claim 14, wherein z is zero;

and at least about 80% of the occurrences of x and y are not zero.

17. The SPEM of claim 1, wherein the SPEM is substantially thermally stable to temperatures of at least about 100°

C.

18. The SPEM of claim 1, wherein the SPEM is substantially thermally stable to temperatures of at least about 100°

C. to at least about 175250°

C.

19. The SPEM of claim 1, wherein the SPEM is stable from at least about 100°

C. to at least about 150°

C.

20. The SPEM of claim 1, wherein the SPEM is stable from at least about 120°

C. to at least about 175°

C.

21. The SPEM of claim 1, wherein the SPEM is substantially stable to temperatures of at least about 120°

C.

22. The SPEM of claim 1, wherein the porous polymer substrate comprises a microinfrastructure substantially interpenetrated with the ion-conducting material.

23. The SPEM of claim 1, wherein the porous polymer substrate comprises an extruded or cast film.

24. The SPEM of claim 1, wherein the liquid crystalline polymer substrate comprises a lyotropic liquid crystalline polymer.

25. The SPEM of claim 24, wherein the lyotropic liquid crystalline polymer substrate comprises at least one of a polybenzazole (PBZ) and polyaramid (PAR) polymer.

26. The SPEM of claim 25, wherein the polybenzazole polymer substrate comprises a homopolymer or copolymer of at least one of a polybenzoxazole (PBO), polybenzothiazole (PBT), a poly(diimidazo-pyridine) and polybenzimidazole (PBI) polymer and the polyaramid polymer comprises a homopolymer or copolymer of a polypara-phenylene terephthalamide (PPTA) polymer.

27. The SPEM of claim 26, wherein the polybenzazole polymer substrate comprises a an alternating structure comprising an optionally substituted phenyl or naphthyl group and a repeat unit selected from benzoxazole, benzothiazole, diimidazo-pyridine, and benzimidazole.

28. The SPEM of claim 1, wherein the thermoset or thermoplastic aromatic polymer substrate comprises at least one of a polysulfone (PSU), polyimide (PI), polyphenylene oxide (PPO), polyphenylene sulfoxide (PPSO), polyphenylene sulfide (PPS), polyphenylene sulfide sulfone (PPS/SO₂), polyparaphenylene (PPP), polyphenylquinoxaline (PPQ), polyarylketone (PK) and polyetherketone (PEK) polymer.

29. The SPEM of claim 28, wherein the polysulfone polymer substrate comprises at least one of a polyethersulfone (PES), polyetherethersulfone (PEES), polyarylethersulfone (PAS), polyphenylsulfone (PPSU) and polyphenylenesulfone (PPSO₂) polymer;

the polyimide (PI) polymer comprises a polyetherimide (PEI) polymer;

the polyetherketone (PEK) polymer comprises at least one of a polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketone-ketone (PEKK), polyetheretherketone-ketone (PEEKK) and polyetherketoneetherketone-ketone (PEKEKK) polymer; and

the polyphenylene oxide (PPO) polymer comprises a 2,6-diphenyl PPO or 2,6 dimethyl PPO polymer.

30. The SPEM of claim 1, wherein the pore size of the porous polymer substrate is from about 10 Å

to about 20,000 Å

.

31. The SPEM of claim 30, wherein the pore size is from about 10 Å

to about 2,000 Å

.

32. The SPEM of claim 30, wherein the pore size is from about 500 Å

to about 10,000 Å

.

33. The SPEM of claim 1, wherein the ion-conducting material has an ion-conductivity from about 0.01 S/cm to about 1.0 S/cm.

34. The SPEM of claim 1, wherein the ion-conducting material has an ion-conductivity greater than about 0.1 S/cm.

35. The SPEM of claim 1, wherein the ion-conducting material has an ion-exchange capacity greater than about 2.5 milliequivalents per gram.

36. The SPEM of claim 35, wherein the ion-conducting material has an ion-exchange capacity of between about 2.5 and about 5.0 milliequivalents per gram.

37. The SPEM of claim 1, wherein the SPEM has an area specific resistance from about 0.02 to about 20 Ω

·

cm².

38. The SPEM of claim 1, wherein the SPEM has an area specific resistance of less than about 0.2 Ω

·

cm².

39. The SPEM of claim 1, wherein the SPEM has a thickness from about 0.1 mil. to about 5.0 mil.

40. The SPEM of claim 1, wherein the thickness is about 1 mil.

41. The SPEM of claim 1 , wherein the ion-conducting material comprises one or more antioxidants.

42. The SPEM of claim 1, wherein the ion-conducting material comprises sulfone crosslinkages.

43. A device comprising a composite solid polymer electrolyte membrane in accordance with claim 1.

44. The device of claim 43, wherein the device is a fuel cell.

45. The device of claim 44, wherein the fuel cell is a direct methanol fuel cell or a hydrogen fuel cell.

46. The device of claim 45, wherein the direct methanol fuel cell has a methanol permeation rate of less than about 50 mA/cm² of equivalent current density at 0.5V.