Improvement of PEMFC water management by employing water transport plate as bipolar plate

In this study, a porous hydrophilic water transport plate (WTP) has been employed as a bipolar plate to improve water management in proton exchange membrane fuel cells (PEMFCs). The electric conductivity, gas blocking property, water permeability and wettability of the WTP were characterized. The performance, electrochemical impedance spectroscopy (EIS) and water balance of fuel cells with WTPs and solid plates were evaluated. Benefiting from the humidification and drainage functions of the WTP, the performance of fuel cells with WTPs significantly improved compared with fuel cells with traditional solid plates. As indicated from the experiments, a WTP that was placed on the cathode side is favorable for cell performance and system complexity. Additionally, hydrogen stoichiometry hardly affects the water transport, whereas a decrease in air stoichiometry can switch the main function of the WTP from humidification to water drainage. The results show that the use of WTP technology is promising for water management improvement in PEMFCs.