Engineering porous polymer grafted and piperidine capped anion exchange membranes for high-performance water electrolyzers

Green hydrogen production is pivotal for achieving dual-carbon goals. Anion exchange membrane water electrolysis (AEMWE) represents a leading technology for sustainable hydrogen generation, yet its advancement is largely constrained by the scarcity of high-performance anion exchange membranes (AEMs). This study successfully developed four kinds of composite AEMs by introducing highly porous polymeric fillers (PP) bearing active chloromethyl groups into a quaternized poly( p -triphenyl piperidine) (QPTP) matrix via three distinct approaches: physical blending, interfacial crosslinking, and piperidine capping. The composite AEMs containing an optimal amount of PP filler (0.5 wt%) exhibited expanded free volume and significantly improved microphase separation, which enhanced ionic conductivity while suppressing the swelling ratio. Specifically, CPP-QPTP@Pip-0.5 % membrane developed via a dual-strategy of porous polymer crosslinking and piperidine capping possesses OH − conductivity of 189.9 mS cm −1 , swelling ratio of 24.6 %, and water uptake of 67.9 wt% at 80 °C. Moreover, it also displays excellent alkaline durability, showing loss of OH − conductivity less than 5 % after a 70 d period of immersion in 1 M KOH at 80 °C. The corresponding AEMWE cell exhibits an outstanding current density of 1219 mA cm −2 at 2 V in 1 M KOH (80 °C), along with stable working for 1000 h at a constant current of 500 mA cm −2 . Consequently, the as-obtained AEMs have huge potential for application in the field of AEMWE. It is expected the fabrication of composite AEMs by introducing organic porous fillers, coupled with interfacial crosslinking and cationic group capping on filler, may offer more possibility in terms of expanding the topological structure of AEMs.