“Fishnet-like” ion-selective nanochannels for advanced membranes are designed for the first time to enhance the efficiency and durability of flow batteries. A fishnet-like structure with 10 nm ion-transport channels is achieved by tuning the hydrophobic/hydrophilic nanophase separation structure of the membrane, in which absorbed water molecules are restricted around hydrophilic polyethylenimine (PEI) chains by hydrophobic polybenzimidazole (PBI). Owing to the size-exclusion and high-density protonated amine groups of PEI fishnets, the membrane exhibits ultralow VO²⁺ permeability without sacrificing its ion conductivity, ensuring high energy efficiency of vanadium flow batteries. Furthermore, the demonstrated vanadium flow battery with the fishnet-based membrane steadily run at 120 mA cm⁻² over 2000 cycles (about 120 days). These findings provide a new strategy for the design of high-performance and cost-effective membranes for vanadium flow battery applications.

The poor reversibility of Zn stripping/plating processes leads to unsatisfactory cycling stability of Zn anodes, limiting the practical application of aqueous zinc-ion batteries. Herein, sulfobutylether-β-cyclodextrin (SCD) was introduced into the electrolyte as a multi-functional additive. The zincophilic sulfonate groups were found to interact with Zn²⁺ to modulate the solvation structure, enhance adsorption and govern the adsorption configuration of SCD on the Zn surface. This specific adsorption configuration could in situ construct two planes on the Zn surface with progressively improved affinity to Zn²⁺, which could drive the diffusion of Zn²⁺ through the hydrophobic toroidal inner channel, enable the uniform dispersion of Zn²⁺ flux and facilitate the de-solvation process. The synergistic promotional effect of the functional groups and specific structural features remarkably improved the stability of the Zn anode. With the addition of SCD, the Zn//Cu cell exhibited an extended cycle life of over 3000 cycles with an average CE exceeding 99.7%. The Zn//Zn symmetric cell also demonstrated superior cycling stability of over 3900 h at 2 mA cm⁻². The corresponding Zn//NH₄V₄O₁₀ full cells delivered a higher specific capacity and better cycling stability than cells using bare electrolytes. The assembled pouch cells were also stable for over 300 cycles, demonstrating the practical application potential of this electrolyte in high-performance AZIBs.