Zn-ion capacitors (ZICs) have attracted significant attention as next-generation energy storage systems owing to their eco-friendly nature, high safety, and low cost. Nevertheless, the Zn metal anode is prone to dendrite growth and parasitic side reactions, resulting in poor cycling stability. In this work, Titriplex III (TX), the disodium salt of ethylenediaminetetraacetic acid, is introduced as an additive to a ZnSO4-based electrolyte to address these challenges. Density functional theory and molecular dynamics simulations indicate that TX effectively regulates the Zn2+ solvation structure and modifies the electrode-electrolyte interface. The numerous hydrophilic functional groups in TX molecules disrupt the hydrogen-bonding framework of the ZnSO4 electrolyte, leading to a more uniform Zn2+ solvation sheath and reduced side reactions. Consequently, Zn//Zn symmetric cells with a ZnSO4-TX (0.02) electrolyte deliver stable cycling for over 400 h at 5 mA cm???? 2 and 2.5 mAh cm???? 2, compared to only 128 h for the additive-free system. These results confirm that TX effectively suppresses dendrite formation and promotes uniform Zn deposition. This study provides new insights into the interfacial regulation mechanism of electrolyte additives, offering practical guidance for the rational design of stable aqueous electrolytes in highperformance ZICs.

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