Achieving triple improvements in intrinsic properties for porous flow field materials and the proton exchange membrane fuel cell electrochemical performance

Three-dimensional (3D) porous flow fields have been utilized to achieve ultrahigh power density for proton exchange membrane fuel cells (PEMFCs). However, issues such as the severe corrosion and high interface contact resistance of 3D porous flow field limit the effective enhancement in power density. In this work, porous flow fields with various pore structures, i.e., Ni foam and Ti felt are employed and further decorated with carbon coating using the chemical vapor deposition (CVD) method to improve the anti-corrosion capacity. Meanwhile, the through-plane electrical conductivity and hydrophobicity are collectively improved for Ni foam and Ti felt by the carbon coating. Single fuel cell (FC) tests show that both the peak power density (PPD) and limiting current density (LCD) are improved for PEMFCs assembled with C@Ni foam and C@Ti felt flow fields in the cathode. The corresponding electrochemical impedance spectroscopy (EIS) confirms that the improved PPD (C@Ti felt) is attributed to the collective improvements in electrical conductivity and anti-corrosion capacity, and the improved LCD (C@Ni foam) is attributed to enhanced water removal capacity. The triple improvements in the intrinsic property of porous flow field materials obtained in this work are expected to offer novel approaches for developing PEMFCs with ultrahigh power density.