A series of novel anion exchange membranes (AEMs) were prepared by constructing semi?interpenetrating polymer networks (sIPN) based on imidazole functional brominated polyphenyl ether (ImF?BPPO) and quaternary ammonium polyvinyl alcohol (QPVA). The effects of different contents of QPVA on the comprehensive properties of the composite membranes were systematically studied, the structure of the series composite membranes was analyzed by ¹H?NMR and FT?IR, and the morphology of composite membrane was investigated by SEM, and the ion exchange capacity, water uptake and conductivity and other properties of the composite membranes were tested. The results show that the prepared series of composite membranes have good compatibility and no obvious phase separation phenomenon. When the mass fraction of QPVA was 40%, the water uptake and swelling rate of the composite membrane were 58.2% and 24.6%, respectively. At 80 ℃, the conductivity of the composite membrane reached 67.24 mS/cm. After soaking in 6 mol/L KOH alkaline solution for 168 h, about 90% of the initial conductivity was still retained, indicating that the membrane had good conductivity and alkali resistance stability.

At present, the demand for clean energy is constantly increasing to achieve sustainable development of human society. Among numerous new energy storage and conversion devices, proton exchange membrane fuel cells (PEMFCs) can directly convert chemical energy into electrical energy. Therefore, PEMFCs have been considered to have the merits of high efficiency, safety and wide application, etc. The proton exchange membrane is the core component of PEMFCs. However, the trade?off of proton conductivity and mechanical strength has become the primary challenge to hinder the development of proton exchange membranes. Although significant progress has been made in improving the single performance, the mutual constraints of key technical properties restrict the development of proton exchange membranes. Most importantly, the road to the commercialization of fuel cells is thus tortuous. We believe that the development of flexible proton exchange membranes is a main strategy to solve this technical challenge. Based on this, this article summarizes the recent research progress on flexible proton exchange membranes,including flexible polymer materials, structural optimization, and flexible additive design, expecting to provide inspiration for breaking through the performance bottleneck of flexible proton exchange membranes.