Establishing an Ion‐Sieving Separator by Depositing Oxygen‐Deficient SiO_x Layer for Stabilized Zinc Metal Anode

Abstract

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 Zn2+ permeability and promote Zn2+ transport, can effectively alleviate the abovementioned problems. Ion‐sieving on glass fiber separator by deposition of oxygen‐deficient SiOx layer via active screen plasma technology is achieved. While having chemical composition similar to the glass fiber, the SiOx nanoparticles contain oxygen‐rich vacancies that promoted dissociation of the adsorbed water and generation of the hydroxyl groups. The negatively‐charged hydroxylated SiOx layer can repel SO42− and attract Zn2+, which can alleviate the side reactions. The strong interplay between hydroxyl groups and Zn2+ can boost Zn affinity and yield fast Zn2+ transport. Consequently, the SiOx‐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 cm2) pouch Zn‐based devices, showing remarkable flexibility and practicality.

Realizing High Reversible Zinc Metal Anode by Modulating Surface Chemistry and Crystal Structure

“…As the lower 𝜂 reflects smaller nucleation barrier of Zn 2+ , it is conducive to the more stable and uniform Zn plating/stripping process. [29] For the plasma treated groups, Tafel plots in Figure S16 (Supporting Information) reveal an increment in exchange current density (i 0 ) from 0.995 mA cm −2 (R-Zn) to 3.373 mA cm −2 (P20-Zn), followed by a decrease to 1.993 mA cm −2 (P30-Zn). In contrast, there is no significant difference in i 0 among the stretching treated groups shown in Figure S17 (Supporting Information).…”