Chemical Stability of Anion Exchange Membranes for Alkaline Fuel Cells

Solid-state alkaline fuel cells (AFCs), which utilize anion exchange membranes (AEMs) as their electrolytes, have the potential to provide society with low-cost, long-lasting renewable portable power. However, the chemical stability of AEMs poses a critical challenge that limits the wide scale use of AFCs. This chapter reviews literature findings on the chemical stability of recently developed hydroxide conducting AEMs with various backbone and cation chemical structures, where covalently attached cations in AEMs, include ammonium, phosphonium, sulfonium, guanidinium, imidazolium, pyridinium, quaternized 1,4-diazabicyclo(2,2,2)octane (DABCO), and piperidinium. However, limited chemical analysis has been conducted regarding the chemical stability of AEMs, therefore, this chapter will also discuss earlier work on the chemical stability of small molecule cation analogs in alkaline conditions. In the future, a more fundamental understanding of the chemical stability of AEMs will be required to adequately design robust solid-state AFCs.