Construction of macromolecule cross-linked anion exchange membranes containing free radical inhibitor groups for superior chemical stability

Abstract

In order to achieve high chemical stability of anion exchange membranes (AEMs), polystyrene (PVE) containing free radical inhibitor groups is first used to cross-link fluorinated poly(aryl ether ketone) (PAEK). The crosslinked PAEK is afterwards quaternized with 6-bromohexyltrimethylammonium bromide (QA) to fabricate AEMs. The prepared AEMs show obvious microphase separation with anionic cluster spacing within 8.8–9.3 nm according to the SAXS analysis results. The hydroxide conductivity of the proposed AEMs is in the range of 76.7–97.6 mS cm−1 at 80 °C. It is found that the free radical inhibitor groups as well as the dense cross-linked structure endow the AEMs with excellent resistance against the attack of OH‾ and free radicals. After immersed in 1 mol L−1 KOH at 60 °C for 1000 h, the QPAEK-30PVE membrane exhibits about 75% and 82% of the conductivity and IEC retention rate. Using this membrane as the electrolyte, a peak power density of 329 mW cm−2 is achieved under a cell voltage of 0.66 V at 60 °C by fueling the cell with humidified H2 and O2 without back pressure.