Surfactant-enhanced polymer electrolyte nanocomposite membranes and their use in fuel cells

Abstract

Polymer electrolyte nanocomposite membranes were prepared by using perfluorinated sulfonic acid ionomer (Nafion), non-porous hydrophilic fumed silica (Aerosil 380) and anionic fluoro-surfactant (Zonyl TBS). The fluoro-surfactant contributed to well-dispersion of the silica nanoparticles via increased compatibility with Nafion matrix. The Nafion-silica nanocomposite membranes were evaluated in terms of mechanical (e.g., dimensional change and tensile strength) and electrochemical properties (e.g., proton conductivity and current-voltage (IV) curve). Anionic fluorosurfactant with sulfonic acid groups, Zonyl TBS, in polymer matrix showed better mechanical and electrochemical properties of the polymer electrolyte nanocomposite membrane than any other surfactants-containing nanocomposites. The sulfnoic acid groups in Zonyl TBS offered additional transport of protons. Therefore, the nanocomposite membrane with surfactant exhibited better fuel cell performances (60% higher at 0.6V) than Nafion membrane itself.