Self-crosslinked alkaline electrolyte membranes based on quaternary ammonium poly (ether sulfone) for high-performance alkaline fuel cells

Novel self-crosslinked alkaline electrolyte membranes with high hydroxide ion conductivity, excellent dimensional stability and extraordinary solvent resistance stability are synthesized successfully without using any catalyst or separate crosslinker. Monitored by ¹H NMR analysis, the synthetic process of trimethyl poly (ether sulfone)-methylene quaternary ammonium hydroxide (TPQAOH) is found to be simple and efficient. The chemical and thermal stability of the synthetic SCL-TPQAOH-x membranes are better than other anion exchange membranes. At the same time, the hydroxide ion conductivity of SCL-TPQAOH-0.67 membrane reaches 33 mS cm ^-1 with an IEC value of 1.07 mmol g ^-1 at 80°C, which complies with the requirements of alkaline fuel cells. This investigation also proves that self-crosslinking technology is a very simple and effective approach in improving the performance of alkaline electrolyte membranes.