Flexible Bis-piperidinium Side Chains Construct Highly Conductive and Robust Anion-Exchange Membranes
Jianjun Zhang, Weisheng Yu, Xian Liang, Kaiyu Zhang, Huijuan Wang, Xiaolin Ge, Chengpeng Wei, Wanjie Song, Zijuan Ge, Liang Wu, Tongwen Xu
Abstract
Anion-exchange membranes (AEMs) with high ion conductivity and chemical stability are urgently needed for electrochemical energy storage and conversion technologies, e.g., anion-exchange membrane fuel cells (AEMFCs), redox flow batteries, and water electrolysis cells. Herein, a series of AEMs with aryl-ether-free polymer backbones bearing long flexible alkoxy-containing bis-piperidinium cationic side chains and additional hydrophobic alkyl chains were prepared. Multiple morphology analyses confirm that such a structure can promote the self-assembly of the cationic groups. The resulting interconnected ionic highways accelerate the ion transport of AEMs, which can reach up to 122 mS cm–1 at 80 °C. Moreover, the AEM shows excellent alkaline stability, with 93.4% ion conductivity remaining after aging in 2 M NaOH at 80 °C over 1000 h. The structural design opens an effective strategy for developing highly conductive and chemically robust AEMs.