Enhanced uniformity of reactants and water content in single- and multi-serpentine channel of proton-exchange membrane fuel cell

The design of flow field is one of the most important processes to development proton-exchange membrane fuel cell (PEMFC) and increase performance. Serpentine flow field design is known as its power enhanced ability but it is limited by poor reactant distribution in the gas diffusion layer (GDL), non-uniform water content, and low current in the membrane area. Herein, novel U- and L-shaped flow field designs are developed to improve under-rib convection in PEMFCs. The enhanced under-rib convection increases the oxygen concentration in the GDL and reduces the water content in the GDL–channel interface. The uniformity of water content and current density in the membrane at 0.8–0.4 V are improved, with performance increases of 6 % and 8 % for the 1-path U and L shapes, respectively. Furthermore, the counter and cross flow mode analyses indicate that the U and L shapes improve reactant distribution and ensure uniform current density and water content. The effects of GDL porosity and humidity are investigated to demonstrate the performance improvement in case of low humidity and difficult to diffuse gas reactants in GDL.