Trace Additive‐Driven Interfacial Assembly Orchestrates Zinc Deposition through Hydrogen Bond Network Disruption and Solvation Reconstruction

Abstract The pervasive issues of hydrogen evolution reaction (HER), corrosion, and dendrite growth severely compromise the stability and viability of aqueous zinc batteries. Herein, a trace electrolyte additive, 4,6‐dimethyl‐2‐mercaptopyrimidine (DMP) is presented, which remarkably orchestrates the entire zinc deposition process by precisely manipulating the interfacial chemical environment. Even at a minute concentration of 0.14 wt%, DMP preferentially adsorbs onto the zinc anode surface via electrostatic interactions, forming a stable Zn‐DMP heterogeneous interface with a high local concentration. This engineered interface enacts the disruption of hydrogen bond network at the zinc electrolyte interface, effectively blocking proton transport pathways and significantly reducing free water concentration. Concurrently, DMP molecules directly participate in reconstructing the zinc ion solvation structure, displacing highly active water molecules. This combined action synergistically inhibits HER and parasitic side reactions. The assembled Zn||Zn device exhibits a long cycle life of 6000 h at a 1 mA cm ⁻² . The Zn||Cu device achieves an average coulombic efficiency of 99.6% in 1500 cycles. This work offers profound insights into the multifaceted roles of trace additives, providing a roust theoretical foundation for the ration design of high performance and low‐cost zinc batteries.