Hydrophilic surface modification of bipolar plate
A bipolar plate having hydrophilic surfaces is disclosed. The bipolar plate includes multiple surfaces including channels having channel surfaces. A hydrophilic coating is provided on the surfaces to enhance the water management capabilties of a fuel cell.
1. A product comprising:
a bipolar plate comprising:
a plurality of channels having channel surfaces;
a plurality of lands having land surfaces separating said plurality of channels;
a layer of a conductive coating formed on said land surfaces; and
a hydrophilic coating formed on said channel surfaces and not on the land surfaces.
2. The product of claim 1 wherein said hydrophilic coating comprises at least one of a silicon dioxide coating or a titanium oxide coating.
3. The product of claim 2 wherein said hydrophilic coating comprises a silicon dioxide coating and a titanium oxide coating.
4. The product of claim 2 wherein said hydrophilic coating comprises a silicon dioxide coating.
5. The product of claim 1 wherein said conductive coating comprises gold.
6. The product of claim 1 wherein said conductive coating comprises a conductive polymeric carbon coating.
7. The product of claim 1 further comprising a gas diffusion medium underlying the bipolar plate and an electrode underlying the gas diffusion media.
8. The product of claim 1 further comprising a gas diffusion medium underlying the bipolar plate and a membrane electrode assembly underlying the gas diffusion medium.
9. A method comprising:
providing hydrophilic surfaces on a bipolar plate, comprising:
providing a bipolar plate comprising a plurality of channels having channel surfaces and a plurality of lands having land surfaces separating said plurality of channels;
forming a layer of a conductive coating on said land surfaces; and
forming a hydrophilic coating on said channel surfaces and not on the land surfaces.
10. The method of claim 9 wherein said hydrophilic coating comprises at least one of a silicon dioxide coating or a titanium oxide coating.
11. The method of claim 9 wherein said conductive coating comprises gold.
12. The method of claim 9 wherein said conductive coating comprises a conductive polymeric coating.
13. The method of claim 9 wherein said hydrophilic coating is formed on said channel surfaces using a technique comprising at least one of chemical vapor deposition, physical vapor deposition, plasma polymerization or electrochemical methods.
14. The method of claim 9 further comprising providing a gas diffusion media underlying the bipolar plate and an electrode underlying the gas diffusion media.
15. The method of claim 9 wherein said hydrophilic coating comprises a silicon dioxide coating.