Achieving High Conductivity at Low Ion Exchange Capacity for Anion Exchange Membranes with Electrospun Polyelectrolyte Nanofibers

There has been a “trade-off” between ion exchange capacity (IEC) and mechanical properties in anion exchange membranes. Thinking out of the box, high ion conductivity was realized with only a small amount of ion exchange groups (means low IEC) in this work, by way of constructing highly effective ion channels with electrospun polyelectrolyte nanofibers. At a low IEC of 1.02 mmol g–1, the conductivity of quaternized poly(2,6-dimethyl-1,4-phenylene oxide) nanofiber (QPPONF)/poly(vinyl alcohol) (QPPONF/PVA) composite membranes achieved was 51.5 mS cm–1 at 60 °C, which was much higher than that of the homogenous QPPO casting membrane (20.3 mS cm–1 at 60 °C, IEC = 1.04 mmol g–1). Moreover, 70 wt % QPPONF/PVA composite membrane exhibits an excellent peak power density of 791 mW cm–2 in the H2/O2 fuel cell test.