Multilayered membranes with suppressed fuel crossover for direct methanol fuel cells

In order to reduce the methanol crossover from the anode to the cathode side in direct methanol fuel cells (DMFC), multilayered membranes containing a thin layer of sulfonated poly(etheretherketone) (SPEEK) with different sulfonation levels and thickness and two outer layers of recast Nation have been fabricated and characterized. With a comparable polarization loss in DMFC, the multilayered membranes show a significant reduction in methanol crossover compared to the native Nafion membranes. The sulfonation level and the thickness of the SPEEK middle layer play an important role in the methanol crossover and electrochemical performance. The multilayered membrane approach is a promising strategy to overcome the difficulties of methanol crossover in DMFC. (C) 2003 Elsevier B.V. All rights reserved.