The lack of high-performance and substantial supply of anion-exchange membranes is a major obstacle to future deployment of relevant electrochemical energy devices. Here, we select two isomers (m-terphenyl and p-terphenyl) and balance their ratio to prepare anion-exchange membranes with well-connected and uniformly-distributed ultramicropores based on robust chemical structures. The anion-exchange membranes display high ion-conducting, excellent barrier properties, and stability exceeding 8000 h at 80 °C in alkali. The assembled anion-exchange membranes present a desirable combination of performance and durability in several electrochemical energy storage devices: neutral aqueous organic redox flow batteries (energy efficiency of 77.2% at 100 mA cm⁻², with negligible permeation of redox-active molecules over 1100 h), water electrolysis (current density of 5.4 A cm⁻²at 1.8 V, 90 °C, with durability over 3000 h), and fuel cells (power density of 1.61 W cm⁻²under a catalyst loading of 0.2 mg cm⁻², with open-circuit voltage durability test over 1000 h). As a demonstration of upscaled production, the anion-exchange membranes achieve roll-to-roll manufacturing with a width greater than 1000 mm.

Rotatable spacer increases the motions of ionic side-chain to accelerate both ion and H₂O transport during fuel cell operation.

Precise manipulation of the polyelectrolyte self-assembly process, to form the desired microstructure with ion-conducting channels, is of fundamental and technological importance to many fields, such as fuel cells, flow batteries and electrodialysis. To fabricate anion exchange membranes (AEMs) with highly conductive and alkaline stable ion-conducting channels, we hereby report a strategy for designing self-aggregating side chains with optimized alkaline stability, by inserting dipolar ethylene oxide (EO) spacers in the cationic side chain. Simulation and nano-scale microscopy analyses verify the self-assembly process of the flexible side chain with cation–dipole interaction to construct interconnected ionic highways for fast water and ion transportation. The resulting O-PDQA AEM exhibits higher hydroxide conductivity (106 mS cm⁻¹ at 80 °C) and a competitive peak power density (1.18 W cm⁻² at 70 °C) in alkaline H₂/O₂ single-cell fuel cells. Moreover, O-PDQA shows excellent alkaline stability with over 96% conductivity retention after storage in 2 M NaOH solution at 80 °C for 1080 h. This new concept of introducing dipolar moieties in the cationic side chain can accelerate the development of technologies that involve polyelectrolytes.