Materials and Cell Designs for Bipolar Fuel Cells

Bipolar membranes fuel cells utilizing both anion and cation conductive materials have several advantages compared to their purely acidic or alkaline counterparts due to improved water management and electrode kinetics. Material transport properties play an important role in determining viability of membrane and ionomer materials. Additionally, the material at the cation/anion junction is critical to device performance, as it must conduct ions to the interface in addition to mechanically binding the membranes. A series of devices using different interfacial materials has been fabricated for use in direct methanol and hydrogen fuel cells. 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. This work will drive 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.