Anion exchange membranes for alkaline fuel cells: A review

Recent years have seen extensive research on the preparation and properties of anion exchange membranes. Nevertheless, there is as yet no rigorous scientific classification of these membranes, and the methods of synthesis and characterization. The present review offers a practical classification based on the nature and the properties of anion exchange membranes for alkaline fuel cells, arrived at studying the relevant literature. This review also contains a description and assessment of all polymeric materials potentially suitable for use in alkaline fuel cells, and of their specific properties. Although there is ample literature on anion exchange membranes for various other applications, such as electrodialysis, the number of publications reporting alkaline fuel cell performance is still relatively low compared to their acidic homologues, the proton exchange membrane fuel cell. Two tables at the end of the manuscript offer the reader a comprehensive overview by listing all reviewed commercial and non-commercial anion exchange membranes. Suggestions for further research such as elucidation of the ionic transport mechanisms, AFC testing and important issues like the chemical stability and ionic conductivity are addressed as well.