(357e) Anion Exchange Membrane Fuel Cells

      
Proton exchange membrane fuel cells (PEMFCs) face many obstacles including the
high cost of platinum catalyst and perfluorinated membranes, high
electro-osmotic drag of fuel, and slow kinetics for the electrochemical
reactions. Anion exchange membrane fuel cells (AEMFCs) have the potential to
address many of the problems facing proton-based cells. The high pH environment
in AEMFCs provides faster kinetics for both anode and cathode reactions and
paves the way for use of non-noble catalysts, such as silver and nickel. The
use of hydrocarbon membranes may lower the cost of cells.

       In an
effort to develop an AEMFC, new types of anion exchange membrane (AEM) have
been synthesized, including epoxy cross-linked AEMs. The conductivity and stability
of the membranes has been investigated in terms of ion exchange capacity, and
solubility. The ionomer, which is a soluble form of a membrane in the catalyst,
plays an important role in achieving high performance. In this work, the
formulation of the AEM electrode has been investigated and integrated with
different types of AEMs in an effort to achieving high catalytic activity.

     
Moreover, new fuel cell designs have been conceived using alkaline membranes. A
hybrid fuel cell, which consists of proton exchange membrane and AEM
electrodes, has an advantage at both electrodes due to the more facile reaction
kinetics at high pH.  In addition, a new fuel cell stack design has been described using an AEMFC
and PEMFC in series operating with a single fuel tank servicing both anodes.
The advances in membrane technology and cell design will be discussed.