Self-Humidifying Cs2.5H0.5PW12O40 / Nafion / PTFE Composite Membrane for Proton Exchange Membrane Fuel Cells

Abstract

A Cs2.5H0.5PW12O40/Nafion/polytetrafluoroethylene (PTFE) self-humidifying composite membrane was developed for proton exchange membrane fuel cells. It was prepared by recasting the Cs2.5H0.5PW12O40/Nafion self-humidifying layer onto the two sides of a Nafion/PTFE composite membrane with a solution-recast method. Due to the strong acidic, hydrophilic, and redox properties of Cs2.5H0.5PW12O40, the Cs2.5H0.5PW12O40/Nafion self-humidifying layer not only contributes to humidify the membrane but also contributes to the improvement of the open-circuit voltage of the fuel cell. When the self-humidifying composite membrane was employed as an electrolyte in H-2/O-2 PEMFC, a higher maximum power density value (1.1 W/cm(2)) was obtained than that of Nafion/PTFE composite membrane (0.6 W/cm(2)), under the operating conditions of 70 degrees C and at the humidified temperature of 20 degrees C. (c) 2005 The Electrochemical Society.