Nano-fibers for electrical power generation

1. A method of making a device with a fibrous sheet, the method comprising:

providing a solution comprising a fluorinated polymer;

forming an aggregation of fibers, the aggregation of fibers formed by electrospinning the solution of a fluorinated ion conducting polymer;

forming the fibrous sheet from the aggregation of fibers;

mechanically compacting the fibrous sheet to increase fiber density;

welding fibers together at fiber intersection points by exposing the fibers to a solvent vapor; and

interposing the fibrous sheet between an anode and a cathode.

2. The method of claim 1 wherein the anode and cathode are battery components and the fibrous sheet is a battery separator.

3. The method of claim 1 further comprising placing the fibrous sheet between a catalyst layer and a bipolar metal plate wherein the fibrous sheet is a gas diffusion layer.

4. The method of claim 1 wherein the fluorinated polymer comprises a polymer having perfluorocyclobutyl moieties.

5. The method of claim 4 wherein the fluorinated polymer includes pendant side chains.

6. The method of claim 4 wherein the perfluorocyclobutyl moieties are:

7. The method of claim 4 wherein the fluorinated polymer comprises polymer segments 1 and 2:

[E 1 (SO 2 X) d ]-P 1 -Q 1 -P 2   1

E 2 -P 3 -Q 2 -P 4   2

wherein:

E 1 (SO 2 X) d is a sulfonated aromatic-containing moiety;

E 1 is an aromatic-containing moiety;

E 2 is an unsulfonated aromatic-containing and/or aliphatic-containing moiety;

X is an —OH, a halogen, an ester, or

d is the number of (SO 2 X) d attached to E 1 ;

P 1 , P 2 , P 3 , P 4 are each independently: absent, —O—, —S—, —SO—, —CO—, —SO 2 —, —NR 1 H—, or NR 2 —;

R 2 is C 1-25 alkyl;

R 4 is trifluoromethyl, or C 1-25 alkyl trifluoromethyl; and

Q 1 , Q 2 are each independently a fluorinated cyclobutyl moiety.

8. The method of claim 4 wherein the fluorinated polymer comprises polymer segments 3 and 4:

wherein:

E 1 , E 2 are each independently an aromatic-containing and/or aliphatic-containing moiety;

X is an —OH, a halogen, an ester, or

d is the number of (SO 2 X) d attached to E 1 ;

P 1 , P 2 , P 3 , P 4 are each independently: absent, —O—, —S—, —SO—, —CO—, —SO 2 —, —NH—, or NR 2 —;

R 2 is C 1-25 alkyl;

R 4 is trifluoromethyl, or C 1-25 alkyl, trifluoromethyl;

R 8 (SO 2 X) d is a sulfonated aliphatic or an aromatic-containing moiety; and

Q 1 , Q 2 are each independently a fluorinated cyclobutyl moiety.

9. The method of claim 4 wherein the fluorinated polymer comprises polymer segments 5 and 6:

E 1 (SO 2 X) d -P 1 -Q 1 -P 2   5

E 2 -P 3 -Q 2 -P 4   6

connected by a linking group L 1 to form polymer units 7 and 8:

wherein:

E 1 (SO 2 X) d is a sulfonated aromatic-containing moiety;

E 2 is an unsulfonated aromatic-containing and/or aliphatic-containing moiety;

X is an —OH, a halogen, an ester, or

d is a number of (SO 2 X) functional groups attached to E 1 ;

P 1 , P 2 , P 3 , P 4 are each independently absent, —O—, —S—, —SO—, —SO 2 —, —CO—, —NH—, or NR 2 —;

R 2 is C 1-25 alkyl;

R 4 is trifluoromethyl, or C 1-25 alkyl trifluoromethyl;

Q 1 , Q 2 are each independently a fluorinated cyclobutyl moiety;

i is a number representing repetition of polymer segment 5; and,

j is a number representing repetition of a polymer segment 6.

10. The method of claim 4 wherein the fluorinated polymer comprises polymer segments 9 and 10:

E 1 (SO 2 X) d -P 1 -Q 1 -P 2   9

E 2 (SO 2 X) f -P 3   10

wherein:

E 1 , E 2 is an aromatic or aliphatic-containing moiety wherein at least one of E 1 and E 2 include an aromatic group substituted with —SO 2 X;

X is an —OH, a halogen, an ester, or

d is the number of (SO 2 X) functional groups attached to E 1 ;

f is the number of (SO 2 X) functional groups attached to E 2 ;

P 1 , P 2 , P 3 are each independently absent, —O—, —S—, —SO—, —SO 2 —, —CO—, —NH—, or NR 2 —;

R 2 is C 1-25 alkyl;

R 4 is trifluoromethyl, or C 1-25 alkyl trifluoromethyl; and

Q 1 is a fluorinated cyclobutyl moiety,

with the proviso that when d is greater than zero, f is zero and when f is greater than zero d is zero.

11. The method of claim 1 wherein the fluorinated polymer comprises a perfluorosulfonic acid polymer.

12. The method of claim 1 wherein the fluorinated polymer comprises a copolymer containing a polymerization unit based on a perfluorovinyl compound represented by:

CF 2 ═CF—(OCF 2 CFX 1 ) m —O r —(CF 2 ) q —SO 3 H

where m represents an integer of from 0 to 3, q represents an integer of from 1 to 12, r represents 0 or 1, and X 1 represents a fluorine atom or a trifluoromethyl group and a polymerization unit based on tetrafluoroethylene.

13. The method of claim 1 wherein the solution further comprises a fluoro-elastomer or a fluoro-rubber.

14. The method of claim 1 wherein fibers have an average width from about 5 nanometers to about 10 microns.

15. The method of claim 1 wherein the fibers have an average width from about 10 nanometers to about 5 microns.

16. The method of claim 1 wherein the fluorinated polymer comprises a sulfonated or unsulfonated ion-conducting polymer having perfluorocyclobutyl moieties.

17. A fibrous sheet made by a method comprising:

providing a solution comprising a fluorinated polymer;

forming an aggregation of fibers, the aggregation of fibers formed by electrospinning the solution of a fluorinated ion conducting polymer;

forming the fibrous sheet from the aggregation of fibers; mechanically compacting the fibrous sheet to increase fiber density;

welding fibers together at fiber intersection points by exposing the fibers to a solvent vapor; and

interposing the fibrous sheet between an anode and a cathode.

18. The fibrous sheet of claim 17 wherein the fluorinated polymer comprises a component selected from the group consisting of a polymer having perfluorocyclobutyl moieties, a perfluorosulfonic acid polymer, and combinations thereof.

19. The fibrous sheet of claim 17 wherein the solution further comprises a fluoro-elastomer or a fluoro-rubber.

20. The method of claim 1 wherein the fluorinated polymer has the following formula:

wherein n is from about 10 to about 10,000.