Na5YSi4O12 fast ion conductor protection layer enabled dendrite-free Zn metal anode

Aqueous zinc-ion batteries (AZIBs) are promising for future large-scale energy storage systems, however, suffer from inferior cycling life due to the dendrites growth and side reaction on Zn metal anode. Herein, a fast ion conductor Na5YSi4O12 (NYSO) was synthesized and fabricated as a protection layer of the Zn metal anode. By adjusting the thickness, an optimized NYSO coating of 20.3 µm was obtained and the corresponding symmetry cell demonstrates an extended life span of 1896 h at the current density of 0.5 mA cm−2. In addition, a favorable rate performance of the NYSO@Zn anode at a high current density of 10 mA cm−2 was achieved. Benefiting from the NYSO coating, uniform diffusion and deposition of Zn2+ on the Zn anode could be realized, leading to the elimination of Zn dendrites and side reactions. Therefore, the aqueous NYSO@Zn|CNT@MnO2 full cell shows superior capacity and cycling stability to that of the bare Zn full cell.