Nanowire-based membrane electrode assemblies for fuel cells
View Patent ↗The present invention discloses nanowires for use in a fuel cell comprising a metal catalyst deposited on a surface of the nanowires. A membrane electrode assembly for a fuel cell is disclosed which generally comprises a proton exchange membrane, an anode electrode, and a cathode electrode, wherein at least one or more of the anode electrode and cathode electrode comprise an interconnected network of the catalyst supported nanowires. Methods are also disclosed for preparing a membrane electrode assembly and fuel cell based upon an interconnected network of nanowires.
1. A composition comprising: a plurality of nanowires attached directly to a support structure comprising graphite, carbon or a carbon composition, the nanowires comprising crystalline silicon, polycrystalline silicon, amorphous silicon, or a mixture thereof; and an electrolyte.
2. The composition of claim 1 , wherein the nanowires are dispersed within the electrolyte.
3. The composition of claim 1 , wherein a portion of the electrolyte is attached to the nanowires.
4. The composition of claim 1 , wherein a portion of the electrolyte is directly linked to the surface of the nanowires.
5. The composition of claim 1 , wherein a portion of the electrolyte forms a continuous or discontinuous film coating on the surface of the nanowires.
6. The composition of claim 1 , wherein a portion of the electrolyte is uniformly wetted on the surface of the nanowires.
7. The composition of claim 1 , wherein the nanowires comprise an interconnected network of nanowires.
8. The composition of claim 7 , wherein the nanowires comprise at least one surface chemical group which forms chemical cross-links between the interconnected nanowires.
9. The composition of claim 1 , wherein the electrolyte comprises a polymer electrolyte comprising an ionomer, a polyethylene oxide, a poly(ethylene succinate), a poly(beta-propiolactone), or a sulfonated fluoropolymer.
10. The composition of claim 1 , wherein the surfaces of the nanowires are functionalized.
11. The composition of claim 10 , wherein the nanowires are functionalized with at least one functional group which promotes wetting of the electrolyte on the nanowires.
12. The composition of claim 10 , wherein the nanowires are functionalized with at least one functional group which binds the electrolyte to the nanowires.
13. The composition of claim 10 , wherein the nanowires are functionalized with at least one molecule selected from the group consisting of: a short chain polymer, a sulfonated hydrocarbon, a short chain sulfonated hydrocarbon, a fluorocarbon, a short chain fluorocarbon, and a branched hydrocarbon.
14. The composition of claim 10 , wherein the nanowires are functionalized with at least one functional group selected from the group consisting of: a nitric acid group, a carboxylic acid group, a hydroxyl group, an amine group, a sulfonic acid group, or a silane group.
15. The composition of claim 1 , wherein the composition is porous, wherein the porous composition comprises pores disposed between the nanowires of the plurality of nanowires.
16. The composition of claim 15 , wherein the electrolyte is disposed within the pores of the porous composition.
17. The composition of claim 1 , wherein the nanowires comprise a core and one or more shell layers disposed on the core.
18. The composition of claim 1 , further comprising one or more metal catalyst particles attached to the nanowires, wherein the metal catalyst particles comprise gold, copper, or mixtures or alloys thereof.
19. The composition of claim 1 , wherein the nanowires are grown on the support structure.
20. The composition of claim 1 , wherein the composition is electrically conductive.
21. An electrode comprising the composition of claim 1 .
22. An anode comprising the composition of claim 1 .
23. An article, comprising:
an anode;
a cathode;
an electrolyte, and
wherein the anode comprises a substrate and a plurality of nanowires attached directly to the substrate, the substrate comprises graphite, carbon or a carbon composition, and the nanowires comprise crystalline silicon, polycrystalline silicon, amorphous silicon, or a mixture thereof.
24. The article of claim 23 , wherein the nanowires are grown on the substrate.
25. The article of claim 23 , wherein a portion of the electrolyte is directly linked to the surface of the nanowires.
26. The article of claim 23 , wherein a portion of the electrolyte forms a continuous or discontinuous film coating on the surface of the nanowires.
27. The article of claim 23 , wherein the nanowires are functionalized with at least one functional group which binds the electrolyte to the nanowires.
28. The article of claim 23 , wherein the substrate is porous.