γ-Al2O3 coating layer confining zinc dendrite growth for high stability aqueous rechargeable zinc-ion batteries

Zinc is a widely used anode material for zinc-ion batteries. However, the problems of dendrites and side reactions faced by the metal zinc anode limit its cycle stability and service life. Surface modification is a simple and effective strategy for preparing high-performance anodes. Here, we used a simple method to coat the gamma-Al2O3 on surface of metal zinc as an artificial protective layer for the anode/electrolyte. gamma-Al2O3 coating can guide the uniform deposition of zinc ions. The coating has good hydrophilicity, which is conducive to accelerate ion transmission. In addition, the importance of controlling the thickness of protective layer on surface of zinc metal anode to obtain good electrochemical performance is emphasized. The appropriate thickness of Al2O3 coating ensures the rapid migration of zinc ions and improves the uniformity of zinc plating/stripping, which is conducive to more uniform zinc nucleation and high-quality deposition. Therefore, the discharge capacity of Zn@Al2O3-15 full cell at a current density of 0.3 A g(-1) is 174.3 mAh g(-1), which is much higher than that of bare zinc cell (71.8 mAh g(-1)). This work has certain reference significance for the development of anode coating strategies in zinc-ion batteries.

Automated summary

The study demonstrates that coating the gamma-Al2O3 on the surface of the metal zinc anode as an artificial protective layer can enhance the uniform deposition of zinc ions and improve electrochemical performance.