Alkali-Stable Cations and Anion Exchange Membranes

Anion exchange membranes (AEMs) based energy conversion and storage devices have attracted attention as an innovative technology due to their advantageous alkaline catalytic kinetics and cost-effectiveness. AEMs play a crucial role in these devices and have shown significant progress in terms of ionic conductivity, mechanical properties, alkaline stability, and other essential characteristics. Nevertheless, their durability remains a limiting factor preventing the large-scale deployment of AEMs based devices. The attack of hydroxide ions on the cations is an inherent issue that needs to be addressed to enhance the lifetime of the AEMs. Therefore, the design of more stable cationic groups is essential to maintain the initial properties of AEMs and extend the device lifetime. This concept systematically summarizes the development and stability enhancement strategies of the cationic groups for AEMs in recent years, with particular emphasis on the emerging cyclic cationic groups. Furthermore, the stability differences of cations in small molecules versus AEMs are systematically discussed, as well as prospective research toward stable AEMs.