Aqueous zinc-ion batteries (AZIBs) have inherent merits, such as a low price, good safety and high volumetric capacity, and have promising potential for widespread applications. However, the unexpected issues posed by both water-induced side reactions and the uncontrollable growth of zinc dendrites on the zinc anode–electrolyte interface have significantly hindered the widespread application of AZIBs. In this work, barbital (Bb), which has two amide groups, was introduced into a ZnSO₄ electrolyte to create a Bb@ZnSO₄ electrolyte. The hydrolysis of the amide groups resulted in the formation of strong polar groups (carboxyl and amino), which could efficiently anchor zinc ions. Specifically, through the derivation of Bb, it was possible to adjust the Zn²⁺ solvation structure, decreasing the coordinated active SO₄²⁻/H₂O and promoting the anchoring of these species on the surface of the zinc anode. This process provided electrostatic shielding and isolates the SO₄²⁻/H₂O, demonstrating an interface regulating effect and synergistic solvation. Therefore, Bb could mitigate electrochemical corrosion and facilitate dendrite-free homogeneous zinc deposition. As a consequence, the assembled asymmetric Zn∥V₂O₅ full cell utilizing the Bb@ZnSO₄ electrolyte showed highest specific capacities of 294.9 and 92.7 mA h g⁻¹ at 0.1 and 1 A g⁻¹, much higher than the Zn∥V₂O₅ full cell with the ZnSO₄ electrolyte, which delivered specific capacities of 161.1 and 3.0 mA h g⁻¹ at the same current densities. These findings promise to realize the practical application of Bb as an efficient additive in high-performance AZIBs.