A Different Flow Field Design Approach for Performance Improvement of a PEMFC

Flow fields influence the deployment of the reactant gases over the surface of catalyst layer and the removal of the produced water from the cell. An optimum flow field design should provide lowest energy loss, uniform mass distribution and minimize pressure drop between inlet and outlet of the gas stream. An even reactant distribution reduces the mass transport losses and thus allows higher power density. This study is focused on flow fields inspired by veins of the tree leaves, which have effective performance improvement by minimizing the pressure drop and even deploy reactant gases without water flooding. The branching of flow channels corresponds to the Murray's law, which is also applicable to plants. Additionally semi cylindrical obstacles were fabricated at the bottom of the daughter channels to increase the diffusion into the gas diffusion layer. Cylindrical obstacles were applied to reduce the concentration losses, especially at the high current densities. Cell performance and current density vs temperature distribution measurements show that the new innovative designs shows a better performance compared to standard serpentine design by 42.1% at 0.4 V operating voltage. Furthermore, homogenous current and temperature distributions and better water removal are achieved.