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

Abstract

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.