(351e) the Fabrication and Use of Bipolar Membrane in Hybrid PEM/AEM Fuel Cells

The Fabrication and Use of Bipolar Membrane in Hybrid
PEM/AEM Fuel Cells

John M. Ahlfield^*†,
Lisha Liu^‡, and Paul A. Kohl^†

^†School of
Chemical and Biomolecular Engineering

^‡School of
Materials Science and Engineering

Georgia Institute of Technology, Atlanta,
GA

Bipolar membranes
fuel cells utilizing both anion and cation conductive materials have several
advantages compared to their purely acidic or alkaline counterparts. The
potential advantages include improved water management through self-hydration and
facile electrode kinetics. Material transport properties play an important role
in determining viability of membrane and ionomer materials. In addition, the
cation-anion junction itself is a critical element in determining device
performance because it must be sufficiently conductive to ionic species and
mechanically stable to withstand the internal pressure from water formation. A
series of electrochemical devices using different bipolar membranes have been
fabricated for use in direct methanol and hydrogen fuel cells. This study
examines both single- and two-membrane systems containing cation-anion
junctions. These fuel cells were characterized by performance metrics and
electrochemical impedance spectroscopy to determine specific areas for improvement
in the bipolar devices. Operation under varying humidity was studied in order
to understand water management necessary for bipolar fuel cells. These results
will be used in the future optimization of bipolar devices.

Financial support from US Office of
the Deputy Assistant Secretary of the Army for Defense Exports and Cooperation
(DASA-DE&C) is gratefully acknowledged.