A Simple Route to Fabricate an Artificial Interface Protective Layer on a Zn Anode for Aqueous Zn-Ion Batteries

Aqueous Zn-ion batteries (AZIBs) have attracted lots of attention due to good eco-friendly, safety and high energy density. However, the dendritic growth and side reactions on Zn anodes have affected the safety and stability of AZIBs. In this paper, an artificial interface protective layer on the Zn anode has been fabricated by a convenient and straightforward replacement reaction of Bi(CF3SO3)(3) with Zn anode in dimethoxyethane (DME) solution at room temperature. The Ar+ etching X-ray photoelectron spectrometer (XPS) proves that the protective layer is composed of metal Bi, ZnS and ZnSO3, suggesting the success of replacement reaction. This artificial protective layer is propitious to control nucleation sites of Zn2+ and favorable Maxwell-Wagner polarization, resulting in uniform Zn stripping/plating. In addition, the scanning electron microscope (SEM), Tafel plots and X-ray diffraction (XRD) demonstrate that the interface layer can effectively suppress side reactions and dendrite growth. Therefore, the symmetric cells with modified Zn anode exhibit superior cycling stability at diverse current densities with a fixed capacity of 1 mAh cm(-2) and higher coulombic efficiency (CE) than half-cells with pristine Zn anode. Simultaneously, modified Zn/NH4V4O10 full-cells present higher specific capacity, superior cycling stability and rate capability. This simple method provides a new way to modify the Zn anodes for the development of industrialization of aqueous rechargeable ZIBs.

Automated summary

In this study, an artificial interface protective layer was fabricated on the Zn anode to suppress dendritic growth and side reactions, improving the safety and stability of Zn-ion batteries. The protective layer controlled nucleation sites of Zn2+ and enabled uniform Zn stripping/plating, effectively inhibiting side reactions and dendrite growth. The modified Zn anodes exhibited superior cycling stability and coulombic efficiency.