Direct Glycerol Fuel Cell with Polytetrafluoroethylene (PTFE) Thin Film Separator

Anion-exchange membrane direct glycerol fuel cells can yield a high power density, but challenges exist in developing chemically stable ion exchange membranes. In this work, we demonstrate a porous PTFE thin film, a well-known chemical, electro-chemical, and thermal robust material can work as a separator, and achieved high performance of direct glycerol fuel cells (DGFCs). DGFC using PTFE thin film with PdAg/CNT anode catalyst exhibit a remarkable peak power density of 214.7 mW cm^-2, which is about 22.6% lower than state-of-art AEM fuel cell with A901 membrane. The durability test was performed in order to evaluate the degradation rate of cell voltage of both PTFE thin film and A901 membrane. We report a 5.81% and 11.08% decrease in cell voltage for PTFE thin film and A901 anion-exchange membrane. Transmission electron microscopy (TEM) was used to evaluate the particle size of the anode catalyst after long-term discharge, and the results suggest that the PdAg particle size growth may be the main reason to lead performance drop. Our work shows, development of PTFE thin films could potentially alleviate the expense associated with anion exchange membranes for wide-spread fuel cell applications.