Designing Multi‐functional Separators With Regulated Ion Flux and Selectivity for Macrobian Zinc Ion Batteries

Abstract The success of achieving scale‐up deployment of zinc ion batteries is to selectively regulate the rapid and dendrite‐free growth of zinc anodes. Herein, this is proposed that a creative design strategy of constructing multi‐functional separators (MFS) to stabilize the zinc anodes. By in situ decorating metal‐organic‐framework coating on commercial glass fiber, the upgraded separator is of remarkable benefit for strong anion (SO 4 2− ) anchoring, uniform ion flux across the interface, and boosted Zn 2+ desolvation. Such a feature selectively promotes the Zn 2+ transportation efficiency, which enables a high Zn 2+ transference number of 0.81, enhanced ionic conductivity, and a superb exchange current density of 12.80 mA cm −2 . Consequently, the zinc anode can be operated stably with an ultra‐long service lifetime of over 4800 h in symmetric cells and improved cycling endurance in full batteries. This work paves an attractive pathway to design multi‐functional separators with regulated ion flux and selectivity toward high‐energy metal batteries beyond zinc chemistry.