Study on the effect mechanism of functional graphene oxide on the performance of polymer electrolyte membrane for fuel cells

In this paper, amino-phosphate bifunctionalized graphene oxide (PA-GO) was successfully synthesized by amination reaction of graphene oxide followed by acid modification with hypophosphorous acid. A series of composite proton exchange membranes were successfully prepared by adding modified GO to sulfonated poly (aryl ether ketone sulfone) matrices containing carboxyl groups (C-SPAEKS). The prepared composite membranes were performed by a series of tests. The C-SPAEKS@1%PA-GO had the best performance, which was able to achieve the tensile strength of 42 MPa while possessing the high proton conductivity of 128.23 mS cm⁻¹ at 80 °C. In addition, the peak power density of C-SPAEKS@1%PA-GO reached 677.67 mW cm⁻² at a current density of 2082.8 mA cm⁻², which was almost four times that of the pure membrane (166 mW cm⁻²). And after 44 h at a constant current density of 0.1 A cm⁻², the C-SPAEKS@1%PA-GO membrane could still maintain 54.1 % of the original voltage. It can be seen that our work has achieved certain results, and the functionalized modification of graphene oxide could greatly improve the comprehensive performance of proton exchange membranes (PEMs).