Hydrogen Bond Network Assisted Ultrafast Ion Transport of Anion Exchange Membrane Grafting with Covalent Organic Frameworks for Hydrogen Conversion
Xiaoli Lu, Yi Zhang, Xiaoqin Ma, Caili Yuan, Yuhang Chen, Jingying Guo, Donghui Gao, Yunchuan Tu, Qingfei Liu, Jianchuan Wang, Zidong Wei
Abstract
Abstract The development of anion exchange membranes (AEMs) capable of facilitating rapid hydroxide ion transport, while maintaining robust mechanical stability, is considered a key direction for advancing hydrogen energy conversion systems. Herein, we synthesized a series of AEMs by grafting covalent organic frameworks (COFs) onto triphenylpiperidine copolymer and systematically evaluated the performance of AEMs. The tailored COFs, characterized by an extensive hydrogen bond network and high micro‐porosity, created interconnected high‐speed ion transport channels, significantly reducing the resistance to hydroxide ion conduction. Remarkably, the COF‐grafted membranes exhibited superior ionic conductivity compared to pristine triphenylpiperidine, even at lower ion exchange capacities. Additionally, the crystalline and highly rigid structure of the grafted COFs effectively preserved the mechanical stability of the membranes. The optimized COF‐grafted AEMs demonstrated outstanding performance, achieving a peak power density of 1.54 W cm −2 in H 2 –O 2 fuel cells and exceptional current densities of 4.5 A cm −2 at 2.0 V in 1 m KOH and 1.1 A cm −2 at 2.0 V in pure water at 80 °C. The present work provides an effective strategy for enhancing AEM performance through the grafting of COFs.