Porous lignosulfonate membranes for direct methanol fuel cells

Porous lignosulfonate (LS) membranes were prepared and considered for their potential application in direct methanol fuel cells (DMFC). Membranes were characterized by impedance spectrometry and water uptake measurement. Both their ion exchange capacity (IEC) and water uptake capacity affected porous membrane conductivity. Membrane conductivities were in the range 5-12 mS/cm at 80 degrees C. Membrane electrode assemblies (MEAs) based on lignosulfonate membranes were also prepared and characterized in a single cell in order to determine whether they can be used in a DMFC. The current density at 300 mV was of 42 mA/cm(2) at 80 degrees C. (c) 2005 Elsevier B.V. All rights reserved

Membranen für Polymerelektrolyt-Brennstoffzellen

The polymer electrolyte membrane is the heart of hydrogen fuelled Polymer Electrolyte Fuel Cells (PEFC) and methanol fuelled Direct Methanol Fuel Cells (DMFC). Membranes of sulfonated fluoropolymers are already commercially available. Important goals for research and development are for PEFCs an increased operating temperature without the need for additional humidification and for DMFC the reduction of methanol transport through the membrane. The use of non-fluorinated polymers aims at a reduction in membrane cost and environmental hazards. Membranes already in industrial product development are considered as well as novel membrane concepts in fundamental research