Corrosion resistant, electrically and thermally conductive coating for multiple applications
View Patent ↗Embodiments of an electrically conductive fluid distribution plate are provided, wherein the electrically conductive fluid distribution plate comprises a plate body defining a set of fluid flow channels configured to distribute flow of a fluid across at least one side of said plate, and a coating adhered to the plate in an area of the plate including the fluid flow channels defined by the plate body. The coating comprises expanded graphite comprising less than about 0.01% by weight of impurities. The coating also comprises less than about 10% by weight expanded graphite plus carbon black, and about 70% to about 95% by wt. binder, wherein the binder is comprised of a polymeric resin.
1. An electrically conductive fluid distribution plate comprising:
a plate body defining a set of fluid flow channels configured to distribute flow of a fluid across at least one side of said plate; and
a coating adhered to said plate in an area of said plate including said fluid flow channels defined by said plate body, wherein said coating comprises
expanded graphite comprising less than about 0.01% by weight of impurities,
carbon black, and
a binder,
wherein said coating comprises less than about 10% by weight said expanded graphite plus carbon black, and about 70% to about 95% by wt. binder, the binder being comprised of polymeric resin.
2. A plate as claimed in claim 1 , wherein said plate further comprises a set of fluid flow channels configured to distribute flow of a fluid across first and second sides of said plate.
3. A plate as claimed in claim 1 , wherein said plate body further comprises a first sheet and a second sheet.
4. A plate as claimed in claim 3 , wherein said first sheet is between about 0.002 inches to about 0.02 inches thick.
5. A plate as claimed in claim 3 , wherein said second sheet is between about 0.002 inches to about 0.02 inches thick.
6. A plate as claimed in claim 1 , wherein said plate further comprises a set of fluid flow channels configured to distribute a flow of fluid through said plate body intermediate first and second sides of said plate body.
7. A plate as claimed in claim 1 , wherein said plate is formed from a material comprising a passivating metal or passivating alloy.
8. A plate as claimed in claim 7 , wherein said passivating metal or alloy comprises at least one of titanium, stainless steel, nickel based alloys, and combinations thereof.
9. A plate as claimed in claim 7 , wherein said plate body further comprises a passivating layer on the surface of said passivating metal or passivating alloy.
10. A plate as claimed in claim 1 , wherein said plate is formed from a material selected from the group consisting of a metal, an alloy, and a composite material.
11. A plate as claimed in claim 10 , wherein said metal and said alloy comprise titanium, stainless steel, nickel based alloys, and combinations thereof.
12. A plate as claimed in claim 10 , wherein said composite material comprises graphite filled polymer.
13. A plate as claimed in claim 1 , wherein said coating comprises between about 3.3% by weight and about 10% by weight of said expanded graphite.
14. A plate as claimed in claim 1 , wherein said expanded graphite comprises at least one of expanded graphite, graphite powder, graphite flake, and combinations thereof.
15. A plate as claimed in claim 1 , wherein said expanded graphite is characterized by a particle size between about 5 μm and about 90 μm.
16. A plate as claimed in claim 1 , wherein said coating comprises between about 1.7% by weight and about 10% by weight of said carbon black.
17. A plate as claimed in claim 1 , wherein said carbon black consist essentially of a particle size between about 0.05 μm and about 0.2 μm.
18. A plate as claimed in claim 1 , wherein said coating comprises said expanded graphite and said carbon black at a ratio of about 2:1 by weight.
19. A plate as claimed in claim 1 , wherein said polymeric resin comprises at least one of polyamide imide, polyimide, poly vinyl ester, and combinations thereof.
20. A plate as claimed in claim 1 , wherein said coating comprises less than 2000 ppm of metal contaminants.
21. A plate as claimed in claim 1 , wherein said coating exhibits a contact resistance less than about 20 mohm cm 2 at 200 psi.
22. A plate as claimed in claim 1 , wherein said coating exhibits a contact resistance that does not change significantly under simulated fuel cell conditions.
23. A plate as claimed in claim 1 , wherein said coating exhibits a contact resistance that is substantially the same as the contact resistance of gold.
24. An electrically conductive fluid distribution plate as claimed in claim 1 wherein said coating comprises about 90% by wt. of binder.
25. An electrically conductive fluid distribution plate comprising:
a plate body defining a set of fluid flow channels configured to distribute flow of a fluid across at least one side of said plate; and
a coating adhered to said plate in an area of said plate including said fluid flow channels defined by said plate body, wherein said coating comprises
about 6.7% of expanded graphite, having a particle size of <90 μm and less than about 0.01% by weight of impurities,
about 3.3% of acetylene black, having a particle size of <0.2 μm, and
about 90% of polyamide imide,
wherein said expanded graphite plus carbon black exhibits a contact resistance less than 20 mohm cm 2 at a compression pressure of about 200 psi and greater.