Fluorinated Poly(Aryl Piperidinium) Membranes for Anion Exchange Membrane Fuel Cells.

Anion exchange membrane fuel cells (AEMFCs) are a cost-effective alternative to proton exchange membrane fuel cells (PEMFCs). The development of high performance and durable AEMFCs requires highly conductive and robust anion exchange membranes (AEMs). However, AEMs generally exhibit a trade-off between conductivity and dimensional stability. Here we report a fluorination strategy to create a phase-separated morphological structure in poly(aryl piperidinium) AEMs. The highly hydrophobic perfluoroalkyl side chains augment phase separation to construct interconnected hydrophilic channels for anion transport. As a result, these fluorinated PAP (FPAP) AEMs simultaneously possess high conductivity (> 150 mS cm -1 at 80 °C) and high dimensional stability (swelling ratio < 20% at 80 °C), excellent mechanical properties (tensile strength > 80 MPa and elongation at break > 40%) and chemical stability (> 2000 h in 3 M KOH at 80 °C). AEMFCs with a non-precious Co-Mn spinel cathode using the present FPAP AEMs achieve an outstanding peak power density of 1.31 W cm -2 . The AEMs remain stable over 500 h of fuel cell operation at a constant current density of 0.2 A cm -2 . This article is protected by copyright. All rights reserved.