Dioxole-contained perfluorosulfonated ionomers with different equivalent weights as catalyst binder and proton conductor for proton exchange membrane fuel cells

Improving the oxygen transport ability without sacrificing proton conductivity in cathode catalyst layer is an essential way to increase the performance, thereby reducing platinum usage of proton exchange membrane fuel cells (PEMFCs). Herein, we report the influence of equivalent weight of dioxole-contained highly oxygen permeable perfluorosulfonic acid ionomers as catalyst binder and proton conductor in cathode catalyst layer on the performance of PEMFC. The results reveal that the increase in the fraction of dioxole segments leads to the enhanced oxygen permeation but the decreased proton conductivity in catalyst layer. With optimization of equivalent weight of the synthesized ionomers, the accordingly assembled cell with platinum loading of 0.125 mg cm −2 for both anode and cathode exhibits an improved concentration polarization, leading to an increased peak power density by 166 mW cm −2 at current density of 2900 mA cm −2 compared to Nafion ionomer-based PEMFC at 2800 mA cm −2 using hydrogen and air as reactant gases.