Aqueous Zinc (Zn) metal batteries (AZMBs) offer significant advantages, including high specific capacity, low redox potential, cost-effectiveness, and enhanced safety. However, their practical deployment is hindered by challenges such as the hydrogen evolution reaction (HER), Zn substrate corrosion, and dendrite growth, which collectively degrade battery performance and cyclability. This talk will present our recent advancements in addressing these critical issues. We employed in-situ electrochemical mass spectrometry (ECMS), scanning electrochemical microscopy (SECM) to quantitatively monitor HER during Zn electrodeposition, discovering that even a small fraction of HER (0.3%) significantly impacts long-term battery performance. Our investigation revealed a strong correlation between HER and the porous morphology of electrodeposited Zn, highlighting the detrimental effects of trapped H2 and Zn corrosion during charging. To mitigate these challenges, we also developed a novel additive that effectively alters the Zn2+ solvation matrix and disrupts the hydrogen bond network of free water. This additive significantly suppresses HER and dendrite formation, resulting in a 25-fold improvement in cycle life. Comprehensive characterization techniques, including nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry, density functional theory studies, X-ray diffraction, and X-ray photoelectron spectroscopy, confirmed the formation of ion-conductive SEI components and uniform Zn growth. Overall, this talk will provide crucial insights into HER mechanisms and pave the way for designing more stable and efficient AZMBs, thereby advancing the development of next-generation energy storage technologies.