Injected metal bead channel seal achieved through stamped plate features on fuel cell bipolar plates

Abstract

A fuel cell system with reduced leakage and a method of assembling a fuel cell system. Bipolar plates within the system include reactant channels and coolant channels that are fluidly coupled to inlet and outlet flowpaths, all of which are formed within a coolant-engaging or reactant-engaging surface of the plate. One or more seals are also formed on the fluid-engaging surface to help reduce leakage by maintaining fluid isolation of the reactants and coolant as they flow through their respective channels and flowpaths that are defined between adjacently-placed plates. The seal—with its combination of in-plane and out-of-plane dimensions—forms a substantially hollow volume, into which a plug is placed to reduce the tendency of the seal to form a shunted flow of the coolant or reactant around the intended active area of the plate. A fluid port intersection is integrally formed with the seal and is formed to be fluidly cooperative with the volume, and is capable of accepting the introduction of a fluent precursor of the plug material such that upon curing, the precursor material forms a substantially rigid insert that continuously fills both the volume and intersection, thereby increasing the resistance of the plug to movement and the seal to shunted flow. In one form, the geometry of the fluent material injection site is such that it promotes plug anchoring within its intended location, while also providing a manufacturing aid to visually inspect for plug installation, as well as to serve as a bipolar plate stacking alignment locator and verification.