An electrochemical fuel cell having reactant flow passages with a
non-uniform design to increase reactant access to an adjacent fluid
distribution layer at the outlet region as compared to the inlet region.
In an embodiment, at least one reactant flow passage is narrower at the
inlet than at the outlet, with a substantially constant cross-sectional
area maintained along its length. Coolant channels may optionally be
incorporated in the fluid flow plate to provide increased cooling at the
reactant inlet. The plates may vary in thickness and run in counter-flow
to improve efficient stacking of the fuel cells in a fuel cell stack with
reactant passages of varying depth. In another embodiment, electrically
conductive, masking foil covers a portion of at least one reactant flow
passage in the inlet region, but does not extend the length of the
passage.
