Establishing an Ion-Sieving Separator by Depositing Oxygen-Deficient SiO Layer for Stabilized Zinc Metal Anode.

Stable plating/stripping of Zn metal anode remains a great challenge owing to uncontrollable dendrite growth and side reactions. Ion-sieving separators is a unique and promising solution, that possess Zn permeability and promote Zn transport, can effectively alleviate the abovementioned problems. Ion-sieving on glass fiber separator by deposition of oxygen-deficient SiO layer via active screen plasma technology is achieved. While having chemical composition similar to the glass fiber, the SiO nanoparticles contain oxygen-rich vacancies that promoted dissociation of the adsorbed water and generation of the hydroxyl groups. The negatively-charged hydroxylated SiO layer can repel SO and attract Zn, which can alleviate the side reactions. The strong interplay between hydroxyl groups and Zn can boost Zn affinity and yield fast Zn transport. Consequently, the SiO-deposited GF separator enabled dendrite-free Zn deposition morphology, which displays lower overpotential of 18 mV and longer cycling life over 2000 h for Zn symmetric cell. Such a separator can also be easily scaled up to prepare the high-performance large-area (4 × 6 cm) pouch Zn-based devices, showing remarkable flexibility and practicality.