NAMS 2002 Workshop - ICOM 2008

Fuel Cells I – 2
Monday July 14, 3:00 PM-3:30 PM, Honolulu/Kahuku
Nanocomposite Membranes with Low Methanol Permeability for the Direct
Methanol Fuel Cell
B. Ladewig (Speaker), The University of Queensland, Australia, b.ladewig@uq.edu.au
D. Martin, The University of Queensland, Australia
J. Diniz da Costa, The University of Queensland, Australia
M. Lu, The University of Queensland, Australia
Current perfluorinated polymer membranes for the direct methanol fuel cell allow
an unacceptably high level of methanol crossover from the anode to the cathode
during operation, leading to decreased cell potential, fuel utilization efficiency and
power output. It is therefore desirable to develop a new class of membrane
materials with low methanol permeability, while maintaining high proton
conductivity, and chemical, thermal and mechanical stability.
A range of silicon alkoxide precursors have been used with in-situ sol gel
synthesis to prepare nanocomposite Nafion 117/inorganic membranes. The
resulting nanocomposite membrane transport properties show a very strong
dependence on the surface chemistry of the incorporated nanoparticles. In
particular, using 3-mercaptopropyl trimethoxysilane as a precursor leads to a sixfold
reduction in the methanol permeability, albeit with a slight decrease in proton
conductivity.
Future directions for the development of robust DMFC membranes in our centre
will be discussed with respect to current developments in the field.