Poly(arylene piperidinium)-based anion exchange membranes for water electrolysis

With the increasing depletion of fossil fuels, the energy conversion and storage devices based on AEMs such as water electrolysis for hydrogen production have attracted more and more attention. As a critical component of anion exchange membrane-based water electrolysis, AEMs have not met the practical application requirements due to their poor conductivity and alkaline stability. Although a high conductivity can be achieved by constructing microphase separated morphologies, AEMs still suffer from degradation due to the inherent problems of side reactions such as Hoffman elimination of quaternary ammonium cation groups under alkaline conditions. 44 Designing AEMs with preferential ion transport properties, limited swelling, and robust alkaline stability is still a great challenge today. The chemical composition of the polymers may has great influences on the fine-tuning of ion transport capabilities and produce membranes with other desirable qualities, such as chemical and dimensional stability. 45 Therefore, from the perspective of molecular structure design, this thesis presents the design of a series of poly(arylene piperidinium) polymers with stable N-cyclic cationic groups and crosslinking structures to improve the comprehensive performance of AEMs for water electrolysis applications.