Dual-Cation Interpenetrating Polymer Network Anion Exchange Membrane for Fuel Cells and Water Electrolyzers

Anion exchange membranes (AEMs) play an important role in many electrochemical devices, such as alkaline AEM fuel cells and water electrolyzers, with the inherent anion transportation functionality. High ionic conductivity and excellent mechanical and chemical stability are indispensable for the development of AEMs. In addition, excellent comprehensive properties such as high mechanical strength and high ionic conductivity acquired simultaneously are quite important for their commercialization. Single-cation interpenetrating polymer network (IPN) AEMs, with their mechanical support phase and ion conduction phase interlaced, have been reported in our previous work and showed the potential for addressing the dilemma of conductivity and strength. To further increase the ion exchange capacity, both the polymer networks are ionized to fabricate a kind of dual-cation IPN membrane in this work. The resultant membrane cPVBMP-3.0 cQPPO shows excellent OH– conductivity (160.5 mS cm–1 at 80 °C) and good mechanical strength (>20 MPa). In a H2/air (CO2-free) single cell, a high peak power density of 576 mW cm–2 is achieved. In addition, a current density of 210 mA cm–2 at 1.80 V is observed in pure water electrolysis with a membrane electrode assembly electrolyzer.