Fuel source for a fuel cell
View Patent ↗Fuel sources, fuel cells and methods of operating fuel cells are disclosed. In one aspect, the invention features a fuel source for a fuel cell, including a housing made substantially from a fuel-permeable material, and a fuel in the housing.
1. A fuel source configured to provide fuel in vapor form to a fuel cell, comprising:
a collapsible housing and a fuel selected from the group consisting of methanol, ethanol, and hydrocarbons within the housing,
wherein the housing has an exterior surface and includes a membrane that is permeable to the fuel in vapor form and defines at least 25% of the exterior surface area, and
wherein as the fuel in vapor form passes through the membrane the housing collapses.
2. The fuel source of claim 1 , wherein the membrane has a permeability to the fuel in vapor form of at least about 0.001 g/hr·cm 2 .
3. The fuel source of claim 1 , wherein the membrane comprises a plurality of layers.
4. The fuel source of claim 3 , wherein the membrane comprises a first layer having a fuel permeability different than a fuel permeability of a second layer.
5. The fuel source of claim 3 , wherein the membrane comprises a first layer having a porosity different than a porosity of a second layer.
6. The fuel source of claim 1 , wherein the membrane comprises a material selected from the group consisting of a fluorocarbon polymer, a modified polyethylene, a modified polypropylene, a polycarbonate, a polyimide, a polysulfone, a polysulfide, a polyurethane, a polyester, a polysilicone, poly(1-trimethylsilyl-1-propyne), and poly(4-methyl-2-pentene).
7. The fuel source of claim 1 , wherein the housing comprises an additional membrane, and the membrane and the additional membrane are bonded to define a cavity.
8. The fuel source of claim 1 , wherein the housing is prismatic or cubic.
9. The fuel source of claim 1 , further comprising a pressure-sensitive valve in fluid communication with an interior of the housing.
10. The fuel source of claim 9 , wherein the housing defines the pressure-sensitive valve.
11. The fuel source of claim 1 , wherein the fuel is in the form of a liquid.
12. The fuel source of claim 1 , wherein the fuel is in the form of a gel.
13. The fuel source of claim 1 , wherein the membrane defines at least about 60% of the exterior surface area of the housing.
14. The fuel source of claim 1 , wherein the membrane defines at least about 80% of the exterior surface area of the housing.
15. The fuel source of claim 1 , wherein the housing comprises a preferential folding portion.
16. The fuel source of claim 1 , wherein the membrane has a thickness of between 100 nanometers and 200 micrometers.
17. The fuel source of claim 1 , wherein the membrane is impermeable to water and carbon dioxide.
18. The fuel source of claim 1 , wherein the membrane is impermeable to nitrogen and oxygen.
19. The fuel source of claim 1 , wherein the fuel is methanol.