Hydrogenics Corporation
Fuel cell sub-assembly and method of making it

Abstract:

A sub-assembly for an electrochemical stack, such as a PEM fuel cell stack, has a bipolar plate with sealing material extending from its upper face, around the edge of the bipolar plate, and onto its lower face. The bipolar plate is preferably a combination of an anode plate and a cathode plate defining an internal coolant flow field and bonded together by sealing material which also provides a seal around the coolant flow field. All of the sealing material in the sub-assembly may be one contiguous mass. To make the sub-assembly, anode and cathode plates are loaded into a mold. Liquid sealing material is injected into the mold and fills a gap between the edge of the plates, and portions of the outer faces of the plates, and the mold. In a stack, sub-assemblies are separated by MEAs which at least partially overlap the sealing material on their faces.