Fuel cell separator plate having controlled fiber orientation and method of manufacture
First Claim
1. A composite separator plate for use in a fuel cell stack, of the type having a first surface with a plurality of flow channels formed therein and a second surface opposite said first surface the composite separator plate comprising a polymeric material of 50% to 98% by volume and a fibrous conductive material of 2% to 50% by volume disposed in a through-plane orientation such that the effective resistance of said composite separator plate is less than or equal to 50 milliohms·
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0 Petitions
Accused Products
Abstract
A composite separator plate for a fuel cell having a low-carbon loading and a high-polymer loading is disclosed. The separator plate composition includes a percentage of conductive fibrous filler having a relatively high aspect-ratio oriented through the thickness of the plate to achieve desired electrical and thermal conductivity requirements. A method of manufacturing the fuel separator plate having such fibers disposed in a through-plane orientation is also disclosed. The method includes forming a separator plate having a land height for orienting the fibers in a desired through-plane direction, then removing a portion of the land height to obtained the desired geometric configuration for the separator plate.
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Citations
42 Claims
- 1. A composite separator plate for use in a fuel cell stack, of the type having a first surface with a plurality of flow channels formed therein and a second surface opposite said first surface the composite separator plate comprising a polymeric material of 50% to 98% by volume and a fibrous conductive material of 2% to 50% by volume disposed in a through-plane orientation such that the effective resistance of said composite separator plate is less than or equal to 50 milliohms·
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18. A method of manufacturing a composite separator plate comprising the steps of:
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formulating a composite material having a polymeric material of 50% to 98% by volume and a fibrous conductive material of 2% to 50% by volume;
molding said composite material between a first molding surface defining a first land cavity and a second molding surface having a second land cavity to form a separator plate including a first land having a first land height extending from a first side of said separator plate and a second land having a second land height extending from a second side of said separator plate, said fibrous material being oriented such that a first portion of said fibrous conductive material is disposed in said first land and a second portion of said fibrous conductive material is disposed in said second land;
removing at least a portion of said first land, thereby reducing said first land height and forming a first exposed surface having an end of said first portion of fibrous conductive material terminating proximate said first exposed surface; and
removing at least a portion of said second land, thereby reducing said second land height and forming a second exposed surface having an end of said second portion of fibrous conductive material terminating proximate said second exposed surface. - View Dependent Claims (19, 20, 21, 22, 23, 24)
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25. A composite separator plate comprising:
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a composite material molded to form a first land having a first land height extending from a first side of said separator plate and a second land having a second land height extending from a second side of said separator plate, said composite material including a polymeric material of 50% to 98% by volume and a fibrous conductive material of 2% to 50% by volume oriented such that a first portion of said fibrous material is disposed in said first land and a second portion of said fibrous material is disposed in said second land;
wherein a portion of said first land is removed from said separator plate to reduce said first land height and form a first exposed surface having an end of said first portion of said fibrous conductive material terminating proximate said first exposed surface; and
wherein a portion of said second land is removed from said separator plate to reduce said second land height and form a second exposed surface having an end of said second portion of said fibrous conductive material terminating proximate said second exposed surface. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. A composite separator plate for use in a fuel cell stack, of the type having a first surface with a plurality of flow channels formed therein and a second surface opposite said first surface the composite separator plate comprising a polymeric material and a fibrous conductive material, said fibrous conductive material disposed in a through-plane orientation and present in an amount sufficient to provide a conductive path in said through-plane direction.
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41. A composite separator plate comprising:
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a composite material molded to form a first land having a first land height extending from a first side of said separator plate and a second land having a second land height extending from a second side of said separator plate, said composite material including a polymeric material and a fibrous conductive material said fibrous conductive material oriented such that a first portion of said fibrous material is disposed in said first land and a second portion of said fibrous material is disposed in said second land;
wherein has a portion of said first land is removed from said separator plate to reduce said first land height and form a first exposed surface having an end of said first portion of said fibrous conductive material terminating proximate said first exposed surface;
wherein a portion of said second land is removed from said separator plate to reduce said second land height and form a second exposed surface having an end of said second portion of said fibrous conductive material terminating proximate said second exposed surface; and
wherein said fibrous conductive material is present in an amount sufficient to provide a conductive path from said first land to said second land.
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42. A method of manufacturing a composite separator plate comprising the steps of:
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formulating a composite material having a polymeric material and a fibrous conductive material, said fibrous conductive material present in an amount of up to 50% by volume;
molding said composite material between a first molding surface defining a first land cavity and a second molding surface having a second land cavity to form a separator plate including a first land having a first land height extending from a first side of said separator plate and a second land having a second land height extending from a second side of said separator plate, said fibrous material being oriented such that a first portion of said fibrous conductive material is disposed in said first land and a second portion of said fibrous conductive material is disposed in said second land;
removing at least a portion of said first land, thereby reducing said first land height and forming a first exposed surface having an end of said first portion of fibrous conductive material terminating proximate said first exposed surface; and
removing at least a portion of said second land, thereby reducing said second land height and forming a second exposed surface having an end of said second portion of fibrous conductive material terminating proximate said second exposed surface; and
provided that said fibrous conductive material is present in an amount sufficient to provide a conductive path from said first land to said second land.
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Specification