Realizing highly stable zinc anode via an electrolyte additive shield layer and electrochemical in-situ interface

Due to the poor reversibility and stability of the zinc anode of aqueous zinc ion batteries, the practical application has been seriously restricted. Herein, a highly stable and reversible Zn metal anode was achieved via a novel functional electrolyte additive (1,2-Ethanedisulfonic acid (EDA)), which can construct a dual protective layer of electrolyte additive barrier and in-situ interface. Different from other functional additives, EDA interacts weakly with Zn2+, but it has strong adsorption energy with zinc anode, preventing water molecules from attacking zinc anode. Importantly, an organic/inorganic SEI layer containing SO32-, ZnS-based compounds was electrochemical in-situ formed, which can induce uniform Zn2+ deposition with a limiting 2D diffusion of Zn2+ (within 15 s). These were evidenced by the density functional theory (DFT) calculation, etching X-ray photoelectron spectroscopy (XPS) technology, etc. As a result, a cyclic life of 2940 h at 1 mA cm−2 and 1mAh cm−2 could last for Zn||Zn symmetric cell, while a more than 2000 cycles for Zn|| NH4V4O10 full cell. This work provides new insights into the in-situ SEI film in collaboration with electrolyte additive shield layer to stabilize zinc anode.