Enhanced durability of carbazole-based anion exchange membranes via crosslinking and pore filling: Fabrication and evaluation of anion exchange membrane water electrolysis

Abstract

In this study, A cross-linked composite anion exchange membrane (AEM), QPC-BDME-TMA@PE20μm, is fabricated using 9-(6-Bromohexyl)-9H-carbazole (BHC), the chemical cross-linker bis[2-(N, N-dimethylamino)ethyl] ether (BDME), and a porous polyethylene (PE) substrate to enhance chemical durability in anion exchange membranes water electrolysis (AEMWE). Scanning electron microscopy (SEM) analysis shows a dense, uniform structure with no visible pores. Thermal and mechanical stability assessments demonstrate high structural integrity under alkaline electrolysis conditions. The membrane exhibits high ion exchange capacity (IEC) and OH− conductivity, maintaining over 97 % of its conductivity after 1000 h in 1 M KOH, confirming excellent alkali resistance. It achieves a current density of 875 mA/cm2 at 1.8 V and maintains long-term stability for 120 h under alkaline conditions. These findings suggest that the fabricated membranes offer high durability and electrochemical performance for AEMWE applications.