Feasibility study of porous copper fiber sintered felt: A novel porous flow field in proton exchange membrane fuel cells

A novel porous flow field made of the porous copper fiber sintered felt (PCFSF) is developed for proton exchange membrane (PEM) fuel cells. The feasibility of this material is systematically investigated involving fabrication, characterization and application. The experimental results reveal that a lower cutting speed helps prevent the fibers from formation failure and morphological defects. A lower feed rate and a smaller back-cutting depth both reduce the equivalent diameter of the copper fibers. The sintering temperature, time and pressure combine to affect the formation quality of the PCFSF which has three-dimensional network structure with open pores distributed stochastically. The wettability tests show that the PCFSF is hydrophobic and the contact angle increases with the increase of porosity. The corrosion behaviors of the PCFSF in simulated PEM fuel cell environment prove that the PCFSF without any coating and alloying treatment is not quite competent, although the Cu corrosion does not critically happen in the tested fuel cell. The resistance tests demonstrate that the combined total electrical resistance of the composite bipolar plate is smaller than the graphite plate. The single-cell tests show that the performance of the fuel cell with the PCFSF flow field is acceptable. The effects of the operating parameters such as the anode operating pressure and cathode air flow rate are also explored.