Flow field plate for use in a proton exchange membrane fuel cell

Abstract

A flow field plate for use in a PEM fuel cell using a gaseous fuel and oxidant, comprising a substantially planar surface and a flow field formed in the substantially planar surface is provided. The plate further includes a network of flow passages for supplying the fuel or oxidant to the flow field and a network of flow passages for receiving the gases discharging from the flow field. The flow field includes a plurality of substantially symmetric flow sectors having separate inlets and outlets communicating with the networks of supply and exhaust flow passages, respectively. Each flow sector includes a plurality of substantially parallel flow channels formed in the substantially planar plate surface, with each sector partitioned so as to subdivide the channels into a plurality of sets of channels disposed in serial flow relationship, with each set including a plurality of the channels disposed in parallel flow relationship. Consequently, the fuel or oxidant traverses each sector in a plurality of passes, with the gas flowing through a plurality of channels during each pass. Accordingly, the flow field configuration permits the reactant gases to be transported so as to supply the gases evenly to the entire active area of the corresponding fuel cell electrode with very low reactant gas pressure drop.