Electroformed bipolar plates for fuel cells
A bipolar plate assembly for a fuel cell is provided. The bipolar plate assembly includes a first electroformed unipolar plate disposed adjacent a second electroformed unipolar plate. The first and second unipolar plates are bonded by a plurality of localized electrically and thermally conductive plugs by electroplated material deposited within apertures formed in the substrates onto which the unipolar plates are electroformed. A method for forming the bipolar plate assembly is also described.
1. A method for producing a bipolar plate assembly for a fuel cell stack, the method comprising the steps of:
providing a first substrate and a second substrate, each of the first substrate and the second substrate having an external surface corresponding to a desired flow field pattern, at least one of the first substrate and the second substrate including at least one via formed therein;
immersing the first substrate and the second substrate in a plating bath;
plating a first predetermined thickness of a plating material on the external surfaces of the first substrate and the second substrate;
abutting the first substrate with the second substrate;
plating a second predetermined thickness of a plating material on the external surfaces of the first substrate and the second substrate over at least a portion of the first predetermined thickness, the at least one via filled by the plating material when the second predetermined thickness is achieved to bond the first substrate and the second substrate, an external perimeter between the first substrate and the second substrate joined by the second predetermined thickness of plating material to provide a hermetic seal therebetween; and
withdrawing the first substrate and the second substrate from the plating bath.
2. The method of claim 1 , wherein the first predetermined thickness is between about 3 and 10 micrometers.
3. The method of claim 2 , wherein the second predetermined thickness is between about 3 and 10 micrometers.