Seal material with latent adhesive properties and a method of sealing fuel cell components with same

Abstract

A composition with latent adhesion, fuel cell stack with a bipolar plate assembly with latent adhesion and a method of assembling a fuel cell stack with a seal that has latent adhesion such that reactant or coolant leakage through the seal is reduced. Bipolar plates within the stack 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 thin or low aspect-ratio seals are formed on a metal bead that is integrally formed on a surface of the plate and is used 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. By proper formulation of the precursor materials that make up the seal, the activation of the adhesive bond formed between the seal and an adjacent surface within the fuel cell can be delayed to allow ample time to aligned and compressively join the cell assemblies in a stack housing. This in turn improves the ability of the seal and its adjacent surface to avoid seal damage and concomitant reactant or coolant leakage.