Poly(norbornane-co-aryl piperidinium) membranes and ionomers for anion exchange membrane fuel cells

Low-cost anion exchange membrane fuel cells (AEMFCs) with great development potential still face the challenge of insufficient performance and stability of the anion exchange membranes (AEMs), one of their key components. Poly(aryl piperidinium) (PAP) based AEMs without aryl ether in backbone have been extensively studied and have shown significant advantages in performance and durability. Herein, we present a series of poly(norbornane-co-aryl piperidinium) AEMs and ionomers based on the novel aromatic monomer 2,3-diphenylbicyclo [2.2.1]heptane (DPN). The resulting membranes possess high OH- conductivity (157.1 mS cm(-1) at 80 degrees C), excellent mechanical properties (tensile strength >70 MPa), and favorable alkaline stability (>1500 h durability in 2 M NaOH at 80 degrees C). The hydrophobic and distorted DPN unit effectively promotes the formation of hydrophilic-hydrophobic microphase separation of the membrane. Based on our designed poly(norbornane-co- aryl piperidinium) membranes and ionomers, we demonstrated a peak power density of 0.97 W cm- 2 at 80 degrees C without back pressure in AEMFCs. Compared to the fully aromatic anion exchange ionomers, the ionomer containing distorted DPN unit with lower phenyl adsorption significantly improves the H2/O2 fuel cell performance.