Copper Silicate Nanoneedle Arrays on Reduced Graphene Oxide Like “Shelter Forest” Guiding Zn Gradient Deposition

With the sustainable and efficient development of aqueous zinc ion batteries (AZIBs), the research on addressing the issues of the adaptability and durability of zinc anodes has been hot-topic and is still of great challenge. In this work, inspired by the sand treatment and afforestation of the Gobi Beach in Northwest China to ameliorate the problem of wind and sand encroachment, we propose a material with a morphology similar to that of a “shelter forest”, CuSiO₃ nanoneedles arrays grown on both sides of reduced graphene oxide (rGO@CuSi), as a coating layer on the zinc metal surface to guide Zn gradient deposition. The presence of rGO improves the electrical conductivity of CuSiO₃, and the finite element simulation of the electric field and Zn²⁺ concentration proves that the electric field distribution can be effectively homogenized and the local current density can be reduced for the rGO@CuSi-Zn electrode with the surface presenting the shape of a protective forest. This is due to the abundant pores between the nano-needle array structures on the surface of the electrode, which provides high electron and ion transport paths, and are conducive to achieve uniform Zn deposition, like the principle of wind-sand stabilization by protective forest. Both electrochemical experiments and density functional theory calculations show that the negatively charged surface of rGO@CuSi with good Zn affinity is more capable of guiding Zn²⁺ transport. Thanks to its inherent material and structural characteristics, the rGO@CuSi-Zn anode has a high specific capacity and good cycling stability. This study provides an insight for interface engineering like protective forest to accelerate the commercialization of high-performance Zn-based batteries.