This study investigates the development of aqueous zinc metal batteries (AZMBs) and addresses key challenges such as dendrite formation, hydrogen evolution reaction (HER), and ZnO passivation on the anode. The researchers designed a tetraalkylsulfonamide (TAS) additive to suppress HER, reduce dendrite formation, and enhance cyclability. The TAS molecule effectively replaces water molecules in the Zn²⁺ solvation shell, altering the solvation matrix and disrupting the hydrogen bond network of free water. This is demonstrated through various spectroscopic and theoretical studies. Voltammetry and in situ monitoring reveal suppressed dendritic growth and HER in the presence of TAS. Electrochemical mass spectrometry (ECMS) shows a significant reduction in HER during Zn electrodeposition. The addition of 1 mm TAS improves the cycle life of coin cells from approximately 100 hours to over 2500 hours. TAS also suppresses side product formation, enhancing the stability of Zn metal anodes. The study highlights the effectiveness of TAS in modulating the solvation matrix and its potential as a universal additive for high-performance AZMBs.This study investigates the development of aqueous zinc metal batteries (AZMBs) and addresses key challenges such as dendrite formation, hydrogen evolution reaction (HER), and ZnO passivation on the anode. The researchers designed a tetraalkylsulfonamide (TAS) additive to suppress HER, reduce dendrite formation, and enhance cyclability. The TAS molecule effectively replaces water molecules in the Zn²⁺ solvation shell, altering the solvation matrix and disrupting the hydrogen bond network of free water. This is demonstrated through various spectroscopic and theoretical studies. Voltammetry and in situ monitoring reveal suppressed dendritic growth and HER in the presence of TAS. Electrochemical mass spectrometry (ECMS) shows a significant reduction in HER during Zn electrodeposition. The addition of 1 mm TAS improves the cycle life of coin cells from approximately 100 hours to over 2500 hours. TAS also suppresses side product formation, enhancing the stability of Zn metal anodes. The study highlights the effectiveness of TAS in modulating the solvation matrix and its potential as a universal additive for high-performance AZMBs.