Electrochemical devices, such as fuel cells and electrolyzers, which operate under alkaline conditions, are of interest because they have reduced platinum usage and certain performance advantages. New and improved anion conducting membranes (AEM) have been developed. It is desirable for AEMs to have high molecular weight and low oxygen or fuel permeability.

The anion conducting ionomers used to make the electrodes for fuel cells and electrolyzers share some properties with the membranes, such as chemical stability and high ionic conductivity. However, they differ from membranes in other areas such as oxygen or fuel permeability and molecular weight.

In this study, the performance of a variety of anion conducting ionomers was tested in alkaline fuel cells and electrolyzers. It was found that low molecular weight ionomers gave higher initial and long-term performance. The performance was correlated with materials properties and results from impedance spectroscopy.

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