Tailoring Fluorinated Chain Positioning in Anion Exchange Membranes for Boosted Ion and Water Transport Channels

Anion exchange membranes (AEMs) have advanced anion exchange membrane water electrolyzers (AEMWEs) by achieving high ionic conductivity and controlled swelling, yet balancing hydration-enhanced electrolytic performance and swelling-induced dimensional instability remains a key challenge for scalable application. In this work, we advance beyond conventional cationic grafting modification strategies via the rational design of fluorinated alkyl side chains on hydrophobic polymer backbones, thereby enhancing amphiphilic self-assembly. Such structural engineering facilitates the formation of interconnected pathways that enable efficient hydroxide ion and water transport. The resulting PTA_fcP membrane exhibits a low swelling ratio of 14.38% and an OH^- conductivity of 179.2 mS cm^-1 at 80°C. Notably, the establishment of an efficient alkaline electrolyte transport network enables the PTA_fcP-based electrolyzer to achieve a current density of 7.5 A cm^-2. Furthermore, the electrolyzer incorporating a PTA_fcP membrane demonstrates satisfactory durability over 2000 h of operation, exhibiting a voltage fade rate of only 17.9 µV h^-1 at 0.5 A cm^-2, substantiating its application potential for industrial-scale deployment.