Sulfonate poly(ether ether ketone) incorporated with ammonium ionic liquids for proton exchange membrane fuel cell

Sulfonate poly(ether ether ketone) (SPEEK)/ammonium ionic liquids (AIL) composite membranes were fabricated using the solution casting method. AIL is a triethyl ammonium dihydrogen phosphate ([(CH3CH2)3NXH+] [H2PO4−], TEAP) or triethyl ammonium hydrogen sulfate ([(CH3CH2)3NH+] [HSO4−], TEAS). It was found that SPEEK/AIL composite membranes have glossy exteriors from SEM images. Compared to the SPEEK membrane, the thermal durability and proton conductivity of SPEEK/AIL composite membranes decreases due to the incorporation of the AIL which affects the original proton conduct chain and polymer structure. The proton conductivity of the SPEEK96-15S membrane and SPEEK75-35S membrane goes to 7.06 and 6.94 mS/cm respectively at 393 K. The performance of the proton exchange membrane fuel cell (PEMFC) with the SPEEK96-15S membrane and SPEEK75-35S membrane is better than that with the Nafion212 membrane when H2/O2 was humidified at 333 K.