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

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 (SO₄²⁻) anchoring, uniform ion flux across the interface, and boosted Zn²⁺ desolvation. Such a feature selectively promotes the Zn²⁺ transportation efficiency, which enables a high Zn²⁺ 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.