Organic-inorganic hybrid membranes for a PEMFC operation at intermediate temperatures

Recently, polymer electrolyte membrane fuel cells (PEMFCs) have been investigated extensively as a future energy source to solve a global energy and environmental problem due to their high energy conversion efficiency. As a membrane is recognized to be a key element for more efficient PEMFCs, new classes of polymer electrolytes have been investigated elsewhere. We have also studied new temperature-tolerant electrolytes using organic-inorganic materials such as polydimethylsiloxane, polytetramethylene oxide (PTMO), zirconia, and titania materials. 12-phosphotungstic (PWA) and phosphoric acids as a proton source were incorporated in the hydrophilic interface of organic-inorganic hybrid membranes. In this paper, they were synthetically displayed, and the cell performance for intermediate temperature PEFC using a single membrane electrolyte assembly cell was also investigated. The maximum power densities for zirconium phosphate-PTMO and titania-PTMO-PWA composite membranes were 13 and 30 mW/cm(2), respectively. The cell performance of the membranes increased with increasing cell temperature up to 130 degrees C under saturated humidity conditions. The organic-inorganic hybrid electrolytes synthesized from PTMO with metal alkoxides show promise for applications in intermediate temperature PEFCs. (c) 2006 The Electrochemical Society.