Gradient Structured Separator Enables Stable Aqueous Zinc Metal Batteries.

Developing a functional separator is an important strategy to improve the electrochemical performance of the Zn anode by suppressing the Zn dendrite growth and parasitic side reactions, thus advancing the aqueous zinc-ion batteries. Herein, we experimentally realize functional separator with gradient-structure based on CeF nanoparticles functionalized glass fibers. The experimental and theoretical results confirmed that the functional separator can tailor the Zn flux and restrain SO transport, promoting dense Zn deposition. The strong interaction between CeF nanoparticles and HO separates Zn and HO at the electrolyte/Zn anode interface, suppressing side reactions. Consequently, the Zn||Zn with this separator achieves excellent cycling stability of 2500 h at 1 mA cm and 1 mAh cm and 1000 h at 5 mA cm and 5 mAh cm. This design of a functionalized separator provides a distinctive solution for the development of aqueous zinc-ion batteries.