Layered double hydroxide composite membrane for advanced alkaline water electrolysis

The development of alkaline membranes with high conductivity and stability is a significant challenge for the commercial application of advanced alkaline water electrolysis. In this study, a novel anion exchange membrane (AEM) was fabricated by quaternary ammonium poly (n-methyl-piperidine-co-p-terphenyl) (QAPPT) and Ni-Fe layered double hydroxide (LDH) synthesis for advanced alkaline water electrolysis. The uniform dispersion of Ni-Fe LDH in the QAPPT/Ni-Fe LDH composite membrane was confirmed by scanning electron microscopy, showing that Ni-Fe LDH provides the composite membrane with high OH− conductivity and tensile strength. Among different membrane samples, the QAPPT/3% Ni-Fe LDH composite membrane exhibited the best conductivity with 217.6 mS cm−1 at 80°C. Furthermore, the QAPPT/3% Ni-Fe LDH composite membrane showed outstanding electrolysis performance of 1 A cm−2 at the voltage of 1.824 V at 60°C. According to a long-term stability test, conducted at 500 mA cm−2 for more than 87 h, the QAPPT/3% Ni-Fe LDH composite membrane achieved satisfactory electrolysis voltage. This study's results show that QAPPT/Ni-Fe LDH composite membranes have excellent application prospects in advanced alkaline water electrolysis.