Cross-linked aryl-sulfonated poly(arylene ether ketone) proton exchange membranes for fuel cell

Sulfonated poly(arylene ether ketone) (SPAEK) with pendant carboxylic acid groups was synthesized. The pendant carboxylic acid groups were functionalized by unsaturated groups in order to produce a series of cross-linked SPAEK (CSPAEK) membranes. The cross-linking was employed to limit the high degree of water uptake and improve the dimensional stability of the membrane. The proton conductivity, water uptake, methanol permeability, thermal stability, and cell performance were investigated in order to evaluate the application of the prepared CSPAEK membranes in fuel cell. The CSPAEK80-20% system, CSPAEK membrane with 80% sulfonation and 20% cross-linking degree, exhibited a comparable proton conductivity to Nafion 117 but much lower low methanol permeability – about a half of that of Nafion 117, suggesting that it is a promising candidate as a polymer proton exchange membrane for fuel cells.

► Cross-linked aryl-sulfonated PAEK membranes are prepared for fuel cell application.
► Proton conductivity is comparable to Nafion® 117.
► Methanol permeability is about a half of Nafion® 117.
► Cross-linking reduces water uptake and thus enhances dimensional stability.
► The membrane with 80% sulfonation and 20% cross-linking degree exhibits the best cell performance.