β''-Al2O3 Protecting Layer for Stable Zinc Metal Anodes

Aqueous zinc-ion batteries (AZIB) has attracted considerable attention on account of its low cost, high security and environmental friendliness. Nevertheless, the growing dendrites and corrosion reactions on the surface of zinc anode limit the development of AZIB. Herein, β''-Al2O3 with high ion conductivity was firstly employed as an efficient artificial layer for stabilizing the zinc anode. The optimized β''-Al2O3 layer enables homogeneous ion flux and uniform zinc deposition, significantly suppressing dendrite growth and parasitic reactions. Symmetric cells based on this unique protective layer can stably operate for 1600 h under 1 mA cm−2/1 mAh cm−2. Benefiting from the high-performance zinc metal anode, the full cell paired with the NH4V4O10 cathode delivers a high discharge initial capacity of 400 mAh g-1 at 1 A g-1 and good cycling stability. This simple protecting layer provides a new strategy for the modification of zinc metal anode and accelerates the practical application of AZIB.