This study proposes a reliable electrolyte design for aqueous zinc-ion batteries (AZIBs) using a penta-sodium diethylene-triaminepentaacetic acid (DTPA-Na) additive with intermediate chelation strength. The DTPA-Na additive effectively modulates the anode/electrolyte interface, inhibits water-related side reactions, and mitigates dendrite formation on zinc anodes. Symmetrical Zn|Zn cells with 1.5 wt% DTPA-Na exhibit stable operation for over 3500 hours at 1 mA cm\(^{-2}\). Full cells with Zn|NH\(_4\)V\(_4\)O\(_10\) cathodes show excellent cycling stability with 84.6% capacity retention after 500 cycles at 1 A g\(^{-1}\). The additive reduces hydrogen evolution, corrosion, and modifies Zn\(^{2+}\) diffusion and deposition, leading to highly reversible Zn electrodes. This work provides a practical approach to designing reliable electrolytes for high-performance AZIBs.This study proposes a reliable electrolyte design for aqueous zinc-ion batteries (AZIBs) using a penta-sodium diethylene-triaminepentaacetic acid (DTPA-Na) additive with intermediate chelation strength. The DTPA-Na additive effectively modulates the anode/electrolyte interface, inhibits water-related side reactions, and mitigates dendrite formation on zinc anodes. Symmetrical Zn|Zn cells with 1.5 wt% DTPA-Na exhibit stable operation for over 3500 hours at 1 mA cm\(^{-2}\). Full cells with Zn|NH\(_4\)V\(_4\)O\(_10\) cathodes show excellent cycling stability with 84.6% capacity retention after 500 cycles at 1 A g\(^{-1}\). The additive reduces hydrogen evolution, corrosion, and modifies Zn\(^{2+}\) diffusion and deposition, leading to highly reversible Zn electrodes. This work provides a practical approach to designing reliable electrolytes for high-performance AZIBs.