Poly(aryl piperidinium)-Based AEMs Utilizing Spirobifluorene as a Branching Agent
발표자
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초록
내용
High-performance anion exchange membranes (AEMs) were developed using 9,9′-spirobifluorene as a 3D branching agent, balancing ion conductivity and mechanical stability. Optimizing the terphenyl to biphenyl ratio and the branching agent amount, the AEM achieves high conductivity (≈190 mS cm−1 at 80 °C in 1 M KOH) and excellent mechanical properties, comparable to state-of-the-art membranes. Gas pycnometer and atomic force microscopy studies showed that spirobifluorene enhances the fractional free volume around the membrane's backbone and modulates the phase separation, boosting both ion conductivity and stability. This membrane demonstrated outstanding chemical stability, with no degradation at 80 °C in 1 M KOH over 1,000 h. It exhibited excellent cell performance, achieving a current density of 11.2 A cm−2 at 80 °C and 2 V in 1 M KOH. An in situ membrane stability test at 1 A cm−2 for 500 h showed no significant degradation.