Novel silica/poly(2,6-dimethyl-1,4-phenylene oxide) hybrid anion-exchange membranes for alkaline fuel cells: Effect of silica content and the single cell performance

Poly(2,6-dimethyl-1,4-phenylene oxide) (PPC)-based organic-inorganic hybrid alkaline membranes with enhanced hydroxyl (OH-) conductivity are prepared in response to the relatively low conductivity of previously reported PPO-based systems. The membranes also exhibit higher swelling-resistant properties and the hydroxyl (OH-) conductivity values are comparable to previously reported fluoropolyrnercontaining membranes: 0.012-0.035S cm(-1) in the temperature range 30-90 degrees C. Other favorable properties for fuel cell application include high tensile strengths up to 25 MPa and large ion-exchange capacities in the range 2.01-2.27 mmolg(-1). Beginning-of-life fuel cell testing of a membrane with a thickness of 140 mu m yielded an acceptable H-2/O-2 peak power density of 32 mW cm(-2) when incorporated into an alkaline membrane electrode assembly. Therefore, this class of hybrid membrane is suitable for application in alkaline membrane fuel cells. (C) 2009 Elsevier B.V. All rights reserved.