Facile construction of crosslinked all-carbon-backbone anion-exchange membranes with robust durability

With the aim of preparing highly alkaline stable anion-exchange membranes (AEMs) with desirable ionic exchange capacity (IEC) and swelling, a series of crosslinked poly(4-vinylphenol) (PVP)-based membranes was prepared. A facile crosslinking method using bis(hydroxymethyl)-4-cresol (BHMC) as the crosslinker was introduced in the preparation of AEMs to avoid sacrificing specific functional groups such as -OH in the backbone. It is worth mentioning that the whole procedure for membrane preparation was efficient and easy to handle. The as-prepared membranes exhibited pretty low water uptake and swelling by the introduction of a crosslinked structure. Microphase separation to different extents could be observed in the membranes with different degrees of crosslinking via transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). The QAPVP-5% membrane with an ionic exchange capacity (IEC) of 2.12 meq g(-1) displayed the highest ionic conductivity of 78 mS cm(-1) at 80 degrees C. Moreover, the all-carbon backbone endowed an excellent alkaline stability of the membranes, and the QAPVP-5% membrane still retained 91.3% of its original conductivity after immersing in a 2 M aqueous KOH solution at 80 degrees C for 480 h. A peak power density of 122 mW cm(-2) was also obtained by a single cell equipped with the QAPVP-5% membrane.