Durable, low transient resistence between bipolar plate and diffusion media
A fuel cell includes a first polymer electrolyte membrane (PEM) and a plate having a series of flow channels formed in a first surface. A first diffusion medium is disposed between the first PEM and the plate and is in direct contact with the first surface. A first sealing layer secures the direct contact between the first diffusion media and the plate and seals the first surface.
1 . A fuel cell, comprising:
a first polymer electrolyte membrane (PEM);
a plate having a first series of flow channels formed in a first surface;
a first diffusion medium that is disposed between said first PEM and said plate and that is in direct contact with said first surface; and
a first sealing layer that secures said direct contact between said first diffusion media and said plate and that seals said first surface.
2 . The fuel cell of claim 1 wherein said first sealing layer is an epoxy resin.
3 . The fuel cell of claim 1 wherein said first sealing layer is electrically conductive.
4 . The fuel cell of claim 1 wherein said first sealing layer is electrically non-conductive.
5 . The fuel cell of claim 1 further comprising a first series of lands formed in said plate, wherein said first diffusion media is in direct contact with said first series of lands.
6 . The fuel cell of claim 1 wherein said first sealing layer is initially applied to said first surface in a non-cured state and a portion of said first diffusion media is immersed through said first sealing layer to contact said first surface, said first sealing layer achieving a cured state to secure said first diffusion media to said first surface.
7 . The fuel cell of claim 1 further comprising:
a second series of flow channels formed in a second surface of said plate;
a second diffusion medium that is disposed between a second PEM and said plate and that is in direct contact with said second surface; and
a second sealing layer that secures said direct contact between said first diffusion media and said plate and that seals said second surface.
8 . The fuel cell of claim 7 wherein said second sealing layer is an epoxy resin.
9 . The fuel cell of claim 7 wherein said second sealing layer is electrically conductive.
10 . The fuel cell of claim 7 wherein said second sealing layer is electrically non-conductive.
11 . The fuel cell of claim 7 further comprising a second series of lands formed in said plate, wherein said second diffusion media is in direct contact with said second series of lands.
12 . The fuel cell of claim 7 wherein said second sealing layer is initially applied to said second surface in a non-cured state and a portion of said second diffusion media is immersed into said second sealing layer to contact said second surface, said second sealing layer achieving a cured state to secure said second diffusion media to said second surface.
13 . The fuel cell of claim 7 wherein said plate is a bipolar plate, wherein said first series of flow channels facilitate a cathode feed gas flow and said second series of flow channels facilitate an anode feed gas flow.
14 . The fuel cell of claim 13 wherein said plate includes cooling channels formed therethrough.
15 . A method of assembling a fuel cell, comprising:
applying a first adhesive layer to a cathode surface of a cathode plate in a non-cured state;
pressing a first diffusion media into contact with said cathode surface while said first adhesive layer is in said non-cured state; and
curing said first adhesive layer into a cured state to secure contact between said first diffusion media and said cathode surface and to seal said cathode surface from contact with an cathode feed gas.
16 . The method of claim 15 wherein said first adhesive layer is an epoxy resin.
17 . The method of claim 15 wherein said first adhesive layer is electrically conductive.
18 . The method of claim 15 wherein said first adhesive layer is electrically non-conductive.
19 . The method of claim 15 further comprising removing a poor conducting layer from said cathode surface prior to said step of applying said first adhesive layer.
20 . The method of claim 15 further comprising:
applying a second adhesive layer to an anode surface of an anode plate in a non-cured state;
pressing a second diffusion media into contact with said anode surface while said second adhesive layer is in said non-cured state; and
curing said second adhesive layer into a cured state to secure contact between said second diffusion media and said anode surface and to seal said anode surface from contact with an anode feed gas.
21 . The method of claim 20 wherein said second adhesive layer is an epoxy resin.
22 . The method of claim 20 wherein said second adhesive layer is electrically conductive.
23 . The method of claim 20 wherein said second adhesive layer is electrically non-conductive.
24 . The method of claim 20 further comprising removing a poor conducting layer from said anode surface prior to said step of applying said second adhesive layer.
25 . A fuel cell system, comprising:
a fuel cell stack including a plurality of fuel cells in electrical series connection, each of said plurality of fuel cells comprising:
a polymer electrolyte membrane (PEM);
a cathode plate having a series of cathode flow channels formed in a cathode surface thereof;
a first diffusion medium that is disposed between said first PEM and said plate and that is in direct contact with said cathode surface; and
a first sealing layer that secures said direct contact between said first diffusion media and said plate and that seals said cathode surface; and
26 . The fuel cell system of claim 25 wherein said first sealing layer is an epoxy resin.
27 . The fuel cell system of claim 25 wherein said first sealing layer is electrically conductive.
28 . The fuel cell system of claim 25 wherein said first sealing layer is electrically non-conductive.
29 . The fuel cell system of claim 25 further comprising a first series of lands formed in said plate, wherein said first diffusion media is in direct contact with said first series of lands.
30 . The fuel cell system of claim 25 wherein said first sealing layer is initially applied to said cathode surface in a non-cured state and a portion of said first diffusion media is immersed through said first sealing layer to contact said cathode surface, said first sealing layer achieving a cured state to secure said first diffusion media to said cathode surface.
31 . The fuel cell system of claim 25 further comprising:
an anode plate having a series of anode flow channels formed in an anode surface thereof;
a second diffusion medium that is disposed between a second PEM and said anode plate and that is in direct contact with said anode surface; and
a second sealing layer that secures said direct contact between said second diffusion media and said anode plate and that seals said anode surface.
32 . The fuel cell system of claim 31 wherein said second sealing layer is an epoxy resin.
33 . The fuel cell system of claim 31 wherein said second sealing layer is electrically conductive.
34 . The fuel cell system of claim 31 wherein said second sealing layer is electrically non-conductive.
35 . The fuel cell system of claim 31 further comprising a second series of lands formed in said anode plate, wherein said second diffusion media is in direct contact with said second series of lands.
36 . The fuel cell system of claim 31 wherein said second sealing layer is initially applied to said anode surface in a non-cured state and a portion of said second diffusion media is immersed into said second sealing layer to contact said anode surface, said second sealing layer achieving a cured state to secure said second diffusion media to said anode surface.
37 . The fuel cell of claim 31 wherein said cathode and anode plates constitute a bipolar plate, wherein said cathode flow channels facilitate a cathode feed gas flow and said anode flow channels facilitate an anode feed gas flow.
38 . The fuel cell system of claim 37 wherein said bipolar plate includes cooling channels formed therethrough.