Acid-Etched Self-Assembled Carbonyl Interface toward Dendrite-Free and Long-Cycling Aqueous Zinc Metal Batteries

Uncontrolled dendrite growth, severe parasitic reactions, and sluggish interfacial kinetics at the Zn electrode–electrolyte interface critically impede the commercialization of zinc metal batteries. Herein, an in situ acid-etching strategy was used to automatically fabricate a multifunctional interfacial coating enriched with carbonyl oxygen moieties on zinc foils through aqueous adipic acid treatment (denoted as the AZ@Zn-8 electrode). This engineered surface layer demonstrates enhanced zincophilic characteristics, which significantly improve ion transport kinetics while ensuring a uniform zinc deposition/dissolution behavior during electrochemical processes. The firmly bonded AZ coating on zinc substrates, combined with the strategically oriented (002)_Zn planes, synergistically ensures superior corrosion resistance. Consequently, the AZ@Zn-8 electrodes display an ultralong cycle stability over 4800 h at 2 mA cm^–2. Furthermore, the full cells assembled incorporating LiFePO₄/C and NH₄V₄O₁₀ cathode materials demonstrate an enhanced electrochemical performance. Therefore, the stabilized Zn anode enabled by acid etching to spontaneously form a functional interfacial layer offers a straightforward and efficient approach for aqueous zinc metal batteries.