An in-situ zincophilic and water-shielding interface for durable aqueous zinc-ion battery

Abstract Aqueous zinc-ion batteries (AZIBs) are plagued by water-rich and unstable electrolyte/electrode interface, which results in poor reversibility and short lifespan. Herein, trace sodium perfluorononyloxybenzenesulfonate (OBS) and bismuth potassium citrate (BPC) additives collaboratively construct a zincophilic and water-shielding interface. Both OBS and BPC molecules preferentially adsorb on the Zn anode, forming a H2O-blocking layer to suppress water-induced side reactions. Concurrently, upon cycling, OBS decomposes and forms ZnF2 with high ionic conductivity, while Bi3+ derived from BPC is electrochemically reduced to metallic Bi0, serving as zincophilic nucleation sites. This in-situ formed ZnF2/Bi-modified interface synergistically regulates Zn2+ flux and homogenizes the interfacial electric field. Consequently, the Zn||Zn symmetric cell achieves exceptional cycling stability over 6600 h at 1 mA·cm−2 and 1 mAh·cm−2, and a lifespan over 1000 h at high current density and areal capacity (3 mA·cm−2 and 3 mAh·cm−2). The full cell paired with NH4V4O10 cathode delivers a capacity retention of 95.54% after 500 cycles at 1 A·g−1, substantially outperforming the baseline electrolyte. This streamlined strategy in-situ constructs a multifunctional hybrid interphase, paving a new way for durable and high-performance AZIBs.