Enhanced Water Management of Three-Dimensional Graphene-Ni Foam with Patterned Wettability in a Polymer Electrolyte Membrane Fuel Cell

Development of a novel flow-field design for improving the water management of proton exchange membrane fuel cells (PEMFCs) is critical for realizing a practical high-performance energy conversion system. The conventional serpentine flow-field designs with the two-dimensional channel and rib configuration often cause water accumulation, thus blocking the transport of reactants and interfering with the removal of water, which in turn result in reduced fuel cell performance at high current densities. In this work, hydrophilic polymer grafting into the patterned region of three-dimensional multilayered graphene (MLG)-coated Ni foam is proposed to improve water management in fuel cells. The MLG-coated Ni foam with patterned wettability provides not only a gas transport pathway via the hydrophobic surface of graphene but also a direct drainage pathway through the patterned hydrophilic region, leading to improved mass transport and PEMFC performance at high current densities.