Dynamic Interfacial pH Stabilization and (002) Oriented Deposition Enabled by Histidine-Induced Solid Electrolyte...

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 H₂O-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||MnO₂ 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.