Yongmin Liang

Challenging reinforced composite polymer electrolyte membranes based on disulfonated poly(arylene ether sulfone)-impregnated expanded PTFE for fuel cell applications

An ultrathin, low cost and high performance reinforced composite membrane (20 μm, thick) based on disulfonated poly(arylene ether sulfone)-impregnated polytetrafluoroethylene (PTFE) for polymer electrolyte membrane (PEM) fuel cell application was investigated. For comparison, PTFE-reinforced Nafion® membrane (Nafion/PTFE), pristine disulfonated poly(arylene ether sulfone) membrane (SPSU) and recast Nafion112 membrane (rN112) membrane were employed. The peak power density of a single PEM fuel cell employing the composite membrane (SPSU/PTFE) reached 2.4 W cm−2, twice that of the rN112 membrane. The SPSU/PTFE membrane structure was characterized and confirmed by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), and Fourier transform infrared (FTIR) spectroscopy. The improved interface compatibilty of the two components in the SPSU/PTFE membrane, reflected by enhanced morphology/surface property, was ascribed to the surface pre-treatment of microporous expanded PTFE and the presence of the n-butanol auxiliary solvent in the membrane fabrication process. The excellent single cell performance employing our SPSU/PTFE membrane was attributed to the implementation of ultrathin PTFE-reinforced membrane with low areal resistance and utilization of a high proton conductive SPSU ionomer. Our SPSU/PTFE membrane might indicate or pave a way of fluorine-less or non-fluorinated ionomer membranes to replace Nafion® membranes for PEM fuel cell applications.

A Novel PTFE-Reinforced Multilayer Self-Humidifying Composite Membrane for PEM Fuel Cells

A novel polytetrafluoroethylene (PTFE)-reinforced multilayer self-humidifying composite membrane is developed. The membrane is composed of Nafion-impregnated porous PTFE composite as the central layer and nanosized SiO2 supported Pt catalyst imbedded into Nafion as the two side layers. The proton exchange membrane (PEM) fuel cells employing the self-humidifying membrane (20 mu m thick) under dry H-2/O-2 gave a peak power density of 0.95 W/cm(2) and an open-circuit voltage of 1.032 V. The good membrane performance is attributed to hygroscopic Pt-SiO2 catalyst at the two side layers, which results in enhanced anode side self-humidification function and decreased cathode polarization. (c) 2005 The Electrochemical Society.

A Low-Cost PTFE-Reinforced Integral Multilayered Self-Humidifying Membrane for PEM Fuel Cells

A low-cost polytetrafluoroethylene (PTFE)-reinforced integral multilayered self-humidifying membrane Pt-C/sulfonated poly (ether ether ketone) (SPEEK)/PTFE/Nafion was developed for proton exchange membrane (PEM) fuel cells. The membrane was based on a thin porous PTFE film, by which a Pt/C catalyst dispersed SPEEK resin (as the self-humdifying layer) and a small quantity of Nafion resin (as the antidegradation layer) on each side are bonded. The porous PTFE film tightly bonds with the SPEEK and Nafion resins to form an integral membrane and, accordingly, prevents delamination of the two different resins. Energy dispersive spectroscopy measurements were conducted to characterize the membrane structure. The single cell test of the self-humidifying membrane indicated its self-humidifying function. (c) 2006 The Electrochemical Society.