Polyaromatic anion exchange membranes for alkaline fuel cells with high hydroxide conductivity and alkaline stability

Poly (terphenylene-methyl piperidine-biphenyl) was synthesized using biphenyl, terphenyl, and N-methyl-4-piperidone as raw materials to prepare anion exchange membranes (AEMs). Biphenyl and terphenyl as the copolymer monomers were used to regulate the morphology and properties of the AEMs. The flexible copolymer backbone promoted efficient transport of hydroxyl ions. The obtained AEMs show a high ion conductivity of 49.16 mS/cm at 80°C. Furthermore, the stable piperidine cation and polyarylene chain contributed to the excellent alkaline stability of AEMs that showed only 0.63% deterioration in ion conductivity after soaking in 1 M KOH at 80°C for 720 h. The peak of single cell power density of 54 mW cm −2 was obtained at a load current density of 150.1 mA cm −2 using an aqueous solution containing 1 M methanol and 1 M potassium hydroxide as the anode fuel, and pure oxygen gases as the cathode fuel at 30°C.