Polytetrafluoroethylene (PTFE) reinforced poly(ethersulphone)-poly(vinyl pyrrolidone) composite membrane for high temperature proton exchange membrane fuel cells

A high temperature proton-exchange membrane (PEM), polytetrafluoroethylene-poly(ethersulphone)-poly(vinyl pyrrolidone) (PES-PVP/PTFE) composite membranes, was prepared by impregnating PES-PVP solutions into the porous PTFE films to reinforce the mechanical properties thereof. After doping with phosphoric acid (PA), the tensile strength and Young[U+05F3]s modulus of PES-PVP/PTFE composite membranes were much higher than those of the PA doped PES-PVP membrane. PA doping level of the composite membrane was positively related to the impregnating degree of PES-PVP into PTFE. In this study, the PES-PVP/PTFE composite membranes with the optimized impregnating degree exhibited a proton conductivity of 0.26Scm^-1 at 180°C with 560wt% H₃PO₄ doped. The high-temperature PEMFCs with PES-PVP/PTFE-5 composite membrane demonstrated a maximum power density of 607mWcm^-2 at 180°C with H₂/O₂ system. Furthermore, the PES-PVP/PTFE composite membranes show a low H₂ crossover current density in high-temperature PEMFCs.