Poly(Dibenzothiophene‐Terphenyl Piperidinium) for High‐Performance Anion Exchange Membrane Water Electrolysis

The anion exchange membrane water electrolysis is widely regarded as the next-generation technology for producing green hydrogen. The OH^- conductivity of the anion exchange membrane plays a key role in the practical implementation of this device. Here, we present a series of Z-S-x membranes with dibenzothiophene groups. These membranes contain sulfur-enhanced hydrogen bond networks that link surrounding surface site hopping regions, forming continuous OH^- conducting highways. Z-S-20 has a high through-plane OH^- conductivity of 182±28 mS cm^-1 and ultralong stability of 2650 h in KOH solution at 80 °C. Based on rational design, we achieved a high PGM-free alkaline water electrolysis performance of 7.12 A cm^-2 at 2.0 V in a flow cell and demonstrated durability of 650 h at 2 A cm^-2 at 40 °C with a cell voltage increase of 0.65 mV/h.