Tethering cations to aromatic polymers via flexible spacers to enhance the performance of alkaline fuel cell membranes

Conventional anion-exchange membranes based on aromatic polymers with cationic groups placed in benzylic positions on the polymer backbone normally suffer from poor alkaline stability and limited OH− conductivity. However, recently it has been shown that both the conductivity and alkaline stability of anion-exchange membranes can be significantly enhanced by instead placing the cationic groups on flexible and hydrolytically stable alkyl spacers. The present contribution briefly reviews the latest results and developments concerning this synthetic approach to improved alkaline membranes for fuel cells