Strategies for developing new anion exchange membranes and electrode ionomers

The synthesis of new cationic polymers has accelerated the electrochemical field forward towards emerging anion exchange membrane enabled devices. Due to the lack of standard materials for cell testing and optimization, in addition to the absence of a satisfactory commercial anion exchange membranes capable of high current density for electrochemical devices, research groups are aggressively engaged in synthesizing new membrane materials and electrode ionomers. These materials are seen as critical components for the success of precious metal-free alkaline fuel cells and water electrolyzers, advanced flow batteries, CO₂ reduction electrolysis cells, and other advanced electrochemical devices. For decades Nafion, and its many PFSA-type variants, have facilitated the advancement of many membrane-based electrochemical devices - in most cases operated in acidic media. However, no such standard material exists for anion exchange membranes. This article will discuss the recent evolution of anion exchange membranes geared towards electrochemical technology and point to some key breakthroughs in this field to date.