High-performance anion exchange membranes based on poly(aryl piperidinium): With interpenetrating ion transport channels induced by fluorinated crosslinking and side chains

Abstract

Currently, the trade-off between mechanical stability and electrical conductivity has become one of the challenges in developing high-performance anion exchange membranes. Here, we propose a fluorinated crosslinking strategy to improve the mechanical properties of the membrane while achieving high conductivity. The introduction of hydrophobic fluorination units provides a further driving force for the aggregation of hydrophilic ion clusters within the membrane, forming continuous ion transfer channels within the membrane. The results show that the crosslinked membranes maintain a low swelling rate as well as a high OH– conductivity at 80 °C. Among them, the FPTBP-TMA-7 membrane showed the most comprehensive performance, with a OH– conductivity of 116.9 mS cm−1 and a swelling rate of only 14.1% at 80 °C. The chemical structure of the membranes maintained high stability after immersion in highly concentrated alkaline solutions (2 M NaOH at 80 °C for 720 h), with a conductivity retention rate of over 91.8%. In addition, the FPTBP-TMA-7 based fuel cell achieves a peak power density of 264.2 mA cm−2 at 80 °C, showing an attractive application prospect in alkaline fuel cells.