Preparation and Characterization of ex-situ Silica-Nafion- Nanocomposite Membranes with Different Size Particles for Application in PEM Fuel Cells

摘要

Polymer electrolyte membrane fuel cells (PEMFCs) are promising power supplies for future vehicles and portable devices.1 Operation of PEM fuel cells at temperatures above 120 癈 mitigates carbon monoxide catalyst poisoning and thermal management problems associated with current proton exchange membrane (PEM) fuel cell technology. Perfluorosulfonic acid based membranes,such as Nafion-,have high proton conductivity at low temperatures (< 80 癈),but at higher temperatures conductivity and fuel cell performance rapidly dwindle.2 Nanocomposites with silica particles have been shown to have higher working temperatures than the polyelectrolyte alone with an improvement in mechanical properties as well. These nanocomposites include some prepared with in-situ sol-gel formation of silica particles in Nafion- where the size and the chemistry of the filler (silica) were not controlled3,4and others where polydisperse silica particles were mixed into Nafion-.