Inorganic-metal hybrid coating for stabilizing and regulating aqueous zinc anodes

Abstract

Aqueous zinc ion batteries (ZIBs) are expected to be the next generation of energy storage devices. However, the unwanted dendrites growth on zinc anodes, hydrogen evolution and other side reactions hinder the practical application of ZIBs. Here, we designed a novel inorganic-metal hybrid coating with an optimised electric double layer structure at the zinc anode/electrolyte interface. The hybrid coating effectively promotes ionic desolvation, reduces the nucleation overpotential, and suppresses the 2D diffusion process. Furthermore, the coating has good stability and inhibits the dendrites growth, hydrogen precipitation corrosion, and by-products generation. Consequently, the hybrid coating-modified Zn anode exhibited excellent electrochemical performance. Among them, the symmetric cell was able to cycle for 1480 h at 1 mA cm⁻², 1 mAh cm⁻² with an overpotential of ∼34 mV. The symmetric cell achieved a cycle life of ∼1000 h even at a high current of 3 mA cm⁻². The cycling performance and multiplication rate performance in full cells were also demonstrated. This work shows the effectiveness and feasibility of hybrid coating to modulate zinc anode/electrolyte interface.