Tris‐buffered efficacy: enhancing stability and reversibility of Zn anode by efficient modulation at Zn/electrolyte interface

Abstract Aqueous zinc‐ion batteries (AZIBs) have developed rapidly in recent years but still face several challenges, including zinc dendrites growth, hydrogen evolution reaction, passivation and corrosion. The pH of the electrolyte plays a crucial role in these processes, significantly impacting the stability and reversibility of Zn 2+ deposition. Therefore, pH‐buffer tris (hydroxymethyl) amino methane (tris) is chosen as a versatile electrolyte additive to address these issues. Tris can buffer electrolyte pH at Zn/electrolyte interface by protonated/deprotonated nature of amino group, optimize the coordination environment of zinc solvate ions by its strong interaction with zinc ions, and simultaneously create an in‐situ stable solid electrolyte interface membrane on the zinc anode surface. These synergistic effects effectively restrain dendrite formation and side reactions, resulting in a highly stable and reversible Zn anode, thereby enhancing the electrochemical performance of AZIBs. The Zn||Zn battery with 0.15 wt% tris additives maintains stable cycling for 1500 h at 4 mA·cm −2 and 1120 h at 10 mA·cm −2 . Furthermore, the Coulombic efficiency reaches ~ 99.2% at 4 mA·cm −2 @1 mAh·cm −2 . The Zn||NVO full batteries also demonstrated a stable specific capacity and exceptional capacity retention.