PTFE based composite anion exchange membranes: thermally induced in situ polymerization and direct hydrazine hydrate fuel cell application

Anion exchange membrane fuel cells (AEMFCs) are advantageous over proton exchange membrane fuel cells in terms of electrode reaction kinetics and electrocatalyst versatility. As one of the key materials for this type of fuel cell, AEM transports anions from cathode to anode during cell operation and governs the performance of AEMFC. In this work, we report on the fabrication of a novel type of PTFE based composite anion exchange membrane and its application in direct hydrazine hydrate fuel cells (DHFC). The membrane was prepared viain situ thermal polymerization of chloromethyl monomer in pre-treated PTFE matrix followed by quaternary amination and alkalization. Attributed to a high chloromethyl monomer uptake and a membrane structure featuring "hydrophobic matrix confined hydrophilic domain", the fabricated membrane showed hydroxide conductivity up to 0.049 S cm−1 at room temperature and a maximum DHFC power density of 110 mW cm−2 at a voltage of 0.7 V. Such membranes are promising candidates for application in AEMFC.