Construction of Metal-Organic Interface Layers via Highly Expandable Wet Etching for High Stability Zinc Anode

Aqueous zinc-ion batteries (AZIBs) have gained significant traction in large-scale energy storage due to their notable safety and cost-effectiveness. Nevertheless, their commercialization has been significantly hindered by long-term issues such as dendrite growth, hydrogen evolution reaction, and other side reactions. In this study, it is proposed a chemical wet etching method that is both simple and highly scalable. This method effectively removes the natural passivation layer on the Zn surface, creating a metal-organic artificial interfacial layer (TAU-60@Zn). This layer exhibits a low nucleation barrier and a high ion transfer number, thereby promoting the rapid and uniform deposition of Zn ions. Furthermore, TAU-60@Zn assists in maintaining the pH at the electrolyte/anode interface, thereby effectively hindering the hydrogen evolution reaction and other undesirable side reactions. Consequently, the symmetric cell assembled with TAU-60@Zn attains an exceptional cycle life of over 2925 h at a current density of 5 mA cm^-2, and 180 h at 34.2% depth of discharge (DOD). Furthermore, the full cell with a MnO₂ cathode retains 46% of its capacity after 1000 cycles, compared to just 30% for the MnO₂//Zn cell. This chemical etching strategy offers a promising path forward for the commercial application of AZIBs.