Tailoring Molecular Competitive Adsorption for Stable Ah‐Level Aqueous Zinc Metal Batteries

ABSTRACT The water‐dominated inner Helmholtz plane (IHP) at the electrode/electrolyte interface is a critical factor responsible for notorious parasitic reactions and Zn dendrite growth, which severely limit the development of aqueous zinc‐metal batteries (AZMBs). In this work, we report a universal competitive adsorption strategy to reconstruct the interfacial molecular distribution and induce orderly Zn ²⁺ deposition behavior by introducing DL‐malic acid additive (denoted as DL). Specifically, the DL molecules preferentially adsorb on the Zn anode surface, forming a water‐shielding IHP layer that effectively excludes water molecules. The zincophilic groups within DL provide abundant active sites and homogenize Zn ²⁺ flux, achieving uniform Zn ²⁺ deposition. Moreover, the original hydrogen‐bond network is reset, thereby efficiently suppressing active water‐induced parasitic reactions. As a result, symmetric cells with DL additive exhibit remarkable cycling stability over 8600 cycles at 5 mA cm ⁻² and 1 mAh cm ⁻² , while Zn||Cu asymmetric cells achieve a coulombic efficiency of 99.9% over 3600 cycles. The advanced Zn||I ₂ full cell delivers stable operation for 4000 cycles with 82.7% capacity retention at 1 A g ⁻¹ . Moreover, the Zn||I ₂ pouch cell with limited N/P (1.82) reserves 78.2% capacity after 860 cycles. Surprisingly, an Ah‐level Zn||I ₂ pouch cell maintains marvel stability and reversibility over 220 cycles.