Durable and conductive anion exchange membranes based on Poly(m-triphenyl carbazolyl piperidinium) for water electrolysis

Anion Exchange Membrane Water Electrolysis (AEMWE) is an innovative advancement in hydrogen production, and anion exchange membrane (AEM) is the critical component for AEMWE. Nevertheless, low conductivity and poor alkaline stability of AEM impede the further development of AEMWE technology. In this study, m-triphenyl, carbazole, and N-methyl-4-piperidone were used to construct a polymer without an ether bond in the main chain through Friedel-Crafts polymerization, producing a series of AEMs with microphase separation. The prepared AEM displayed good hydroxide conductivity, with a value of 136 mS cm−1 at 80 °C and an ion exchange capacity (IEC) of 2.13 mmol g−1, as well as being suitable in terms of water uptake and swelling ratio at 61.4 % and 15 % respectively. Upon being soaked in a 1 M NaOH solution at 80 °C for more than 1000 h, the conductivity loss was kept below 10 %. Furthermore, the prepared AEM-based AEMWE achieved current density of 3.2 A cm−2 at voltage of 2 V with 1 M KOH solution at 80 °C, and could be operated for more than 800 h at 80 °C with a low voltage loss of 162 μV h−1. The results reveal that durable and conductive AEMs based on Poly (m-triphenyl carbazolyl piperidinium) as a promising prospect in anion exchange membrane water electrolysis.