He, Zi-FanZi-FanHeWang, Ting-YuTing-YuWangHuang, Ai LingAi LingHuangLai, Chi-YuChi-YuLaiLiao, Yi-ChengYi-ChengLiaoKunnathumpeedika, ShafnaShafnaKunnathumpeedikaHu, Chi-ChangChi-ChangHu2026-09-022026-09-0220262050-7488https://imec-publications.be/handle/20.500.12860/60173Strongly acidic aqueous batteries promise high voltage and fast kinetics but are fundamentally limited by the instability of metal negative electrodes such as Zn. Here, we demonstrate reversible Zn plating/stripping at pH = 0 by regulating the hydronium accessibility at the electrode–electrolyte interface. A defect-engineered MOF-801 coating creates a confined interfacial microenvironment, where the hydrophobic pore entrances can exclude bulk water and the defect-derived –COOH/–OH groups selectively trap hydronium. This regulation reorganizes the inner Helmholtz layer into a hydronium-depleted configuration, inducing the partial Zn2+ desolvation, suppressing hydrogen evolution, and homogenizing the Zn2+ flux. Consequently, the MOF-protected Zn symmetric cells can achieve stable cycling for longer than 1660 h at 1 mA cm−2 in the pH 0 electrolyte. The strategy further enables record performance in Zn–PbO2 (2.35 V), Zn–MnO2 (502.8 Wh kg−1), and Zn-ion hybrid capacitors (30 000 cycles), extending the operational pH boundary of aqueous electrochemistry.engJournal article10.1039/d6ta01825dWOS:001774627900001CORROSION