Dynamic Interfacial pH Stabilization and (002) Oriented Deposition Enabled by Histidine‐Induced Solid Electrolyte Interphase for Highly Reversible Zn Anodes

ABSTRACT Aqueous zinc batteries hold great promise for large‐scale energy storage due to their high energy density, safety, and cost‐effectiveness. However, the intrinsic thermodynamic instability of zinc drives inevitable HER, leading to interfacial accumulation of OH − that significantly exacerbates dendrite growth and “dead zinc” formation. This work leverages the specific structural and reactive properties of histidine (HIS) to construct a Zn(OH) 2 ‐HIS ultrathin solid electrolyte interphase (SEI) on the zinc anode. This SEI stabilizes the interfacial pH via a synergistic mechanism of chemical buffering and physical blocking. Chemically, the imidazole and amino groups buffer the pH via reversible protonation/deprotonation; physically, the SEI disrupts the interfacial hydrogen‐bond network and repels solvated water, thereby suppressing H 2 O‐induced side reactions. Additionally, the SEI modulates interfacial surface energy to enable (002)‐oriented deposition. Consequently, the HIS@Zn anode achieves significantly improved reversibility with a high Coulombic efficiency of 99%. It exhibits ultra‐stable cycling for over 1350 h at 10 mA cm −2 and 5 mAh cm −2 . Even at a high depth of discharge of 81%, stable operation is maintained for over 300 h. Furthermore, the HIS@Zn||MnO 2 full cell delivers an initial capacity of 146.6 mAh g −1 at 1 A g −1 , retaining 92.33% of its capacity after 700 cycles.