Xonotlite nanowire interfacial layer with zincophilic behavior and ion confinement effect guiding inerratic Zn deposition

Aqueous Zn-ion batteries (AZIBs) have garnered huge attention for grid-scale energy storage systems owing to the following advantage: eco-friendliness, affordability, safety, and high specific capacity. Nonetheless, the recyclability is hindered by the corrosion, zinc dendrite and hydrogen evolution reaction. The development of protecting layer for Zn anode is of great meaningful and challenge. In this work, a nanowire-structured xonotlite (calcium silicate hydrate, Ca6Si6O17(OH)2, denoted as CaSi) is successfully synthesized by a facile green route and it is used to construct the protecting layer for Zn anode (named as Zn@CaSi), where CaSi functions as an artificial interfacial layer with zincophilic behavior to guide inerratic Zn deposition by the interaction between electrolyte and anode. Owing to the numerous pores of CaSi nanowires, the Zn@CaSi anode offers vast and stable avenues for facilitating the enhancement of Zn2+ deposition kinetics. Regarding the crystal structure, CaSi featuring 4.38 Å nanopore channels can facilitate the desolvation of hydrated zinc ion via the ion confinement effect, therefore effectively inhibiting the hydrogen evolution reaction and accumulation of by-products. Compared to bare Zn, a significant improvement in the overall performance of the Zn@CaSi anode is achieved. The symmetric cell runs smoothly for 1580 h at a current density of 1 mA cm−2, which is approximately 13 times than that of the bare Zn//Zn symmetric cell. The full cell with the enhanced electrochemical performances also demonstrates the CaSi layer can boost the charge transfer and plating/stripping kinetics. Reconstruction of the electrolyte/anode interface using nanowire-formulated CaSi with zincophilic behavior and porous structure is expected to provide new ideas for the engineering of zinc anode interfaces to achieve high-performance AZIBs.