Enhancing the Chemical Stability of Poly(isatin terphenyl)-Based Anion Exchange Membranes by Cross-Linking with Quaternary Ammonium-Functionalized Noria
Shicheng Xu, Yao Gu, Tianyue Ma, Xin Su, Jinyan Chen, Ronghuan He
Abstract
Anion exchange membranes (AEMs) with superior conductivity and excellent chemical stability are always desired. Herein, tertiary amine-functionalized Noria (FNoria) is synthesized for use as both a cross-linker and free radical scavenger to fabricate AEMs based on quaternized poly(isatin 1-bromo-3,5-diphenylbenzene- co -terphenyl) (QPIBT). The macrocyclic FNoria endows the membranes with suitable microphase separation according to the relevant morphology analysis. An ionic conductivity as high as 115 mS cm –1 is achieved at 80 °C in water by the FNoria-containing membrane. The presence of the FNoria results in a conductivity retention rate ranging within 80–86% after immersing the membranes in 2 mol L –1 KOH aqueous solutions at 80 °C for 1200 h. The membrane-based single fuel cell achieves a peak power density of 1.08 W cm –2 at 80 °C by feeding with humidified H 2 and O 2 under a back pressure of 0.05 MPa. The single fuel cell could retain 77% of its original voltage after operating under a current density of 200 mA cm –2 at 60 °C for 91 h. Fuel cell tests demonstrate the use possibility of the proposed membrane electrolyte.