A microphase separation anion exchange membrane based on poly(terphenyl piperidinium)/cationic polyelectrolyte for high-performance AEMWEs

Anion exchange membrane water electrolyzers (AEMWEs) have undergone rapid development and are increasingly recognized as one of the most promising technologies for hydrogen production in alkaline environments. The advancement of this promising technology is hindered by several limitations associated with anion exchange membranes (AEMs), including inadequate conductivity and insufficient durability. To tackle these challenges during electrolyzer operation, this research presents an effective strategy to construct an ion cluster enriched membrane for high performance AEMWEs. Poly(terphenyl piperidinium), a state-of-the-art AEM, with robust ether-free backbone and alkali-resistant piperidinium functional groups, is adopted as the membrane matrix in this work. A novel DABCO based cationic polyelectrolyte is then synthesized and used as ion transport enhancer by constructing microscopic phase separation. The resultant membrane demonstrates exceptional performance, achieving a high ionic conductivity of 94.2 mS cm -1 and outstanding mechanical properties. A high-performance water electrolysis is achieved with 3185 mA cm -2 at 2 V at 80 o C, which was far from that of commercial FAA and PiperON membrane. Moreover, the water electrolyzer exhibited good in-situ stability at an industrial current density of 800 mA cm -2 for 1400 h, while maintaining a minimal voltage decay rate of 0.109 mV h -1 . This study provides an insightful design strategy for high-performance anion exchange membranes in AEMWEs.