Hydrophilic flexible di-piperidine crosslinked membranes with highly effective ionic channels for water electrolysis

Anion exchange membrane water electrolysis (AEMWE) with low cost and high electrolysis efficiency is an emerging technology for large-scale hydrogen production. High-performance anion exchange membranes (AEMs) are crucial for the commercialization of AEMWE. In this work, four hydrophilic and hydrophobic di-piperidine crosslinked membranes were prepared and tested. The combination of cationic side chains and hydrophilic oxygenated cross-linkers facilitates the construction of efficient and continuous ion transport channels, reducing resistance and enhancing the alkaline stability of AEMs. With cationic side chains and hydrophilic flexible di-piperidine crosslinkers, the PTP-N-QABIEP membrane exhibits high ionic conductivity (151.7 mS cm−1 at 80 °C), good dimensional stability (WU 118.4% and SR 20.2% at 80 °C) and excellent alkaline stability (2 M NaOH > 2300 h at 80 °C). Meanwhile, satisfactory AEMWE performance was demonstrated in 1 M KOH (2.14 A cm−2 and 2.2 V at 60 °C) and pure water (0.600 A cm−2 and 2.2 V at 60 °C), respectively, while there was also a low voltage decay (0.542 mV h−1) after 240 h of operation in 1 M KOH at 500 mA cm−2 and 60 °C. Therefore, the PTP-N-QABIEP membrane with relatively excellent comprehensive performance shows favorable prospects for AEMWE applications in 1 M KOH or pure water.