Sulfone Based Polymers: An Ether-Free and Non-Fluorinated Alternative to Perfluorinated Anion Exchange Membranes in Low Temperature Water Electrolyzers

Several advanced anion exchange membranes have been reported to achieve good ex-situ stability under harsh alkaline conditions without obvious degradation. However, only a handful of them can be stably operated at current densities above 400mA for more than 100hrs in pure water electrolyzers, due to poor oxidative stability. Here we report a series of high-performance non-fluorinated poly(arylene piperidinium sulfone) copolymers (PAPSs) for anion exchange membrane, along with improved pure water AEMWE performance and durability. The copolymers possess high ion conductivity (>130 mS cm -1 ), good mechanical properties (tensile strength > 80 MPa) and good thermal stability. Moreover, PAPS based AEMWEs reach >100 h in-situ durability under 500 mA cm -2 at 60 o C. The presented work provides new non-fluorinated piperidinium cationic based AEMs with improved performance to the fluorinated PAP AEMs for various energy devices.