Engineering Nanoscale Interfacial Solvation Inner-Outer Configuration via Multi-Group Synergy for Practical Zinc...

Rational design of interfacial solvation structures in electric double layer (EDL) remains a critical challenge for aqueous zinc metal batteries (AZMBs). Herein, an efficient multi-group synergy strategy has been proposed to precisely regulate the interfacial solvation structure at nanoscale, which affords long-lifespan AZMBs under high depth of discharge (DOD) and low temperature. Through combined in situ experiments and theoretical simulations, we demonstrate trace multifunctional group biomolecular additive cannot alter electrolyte solvation structure, but contributes to formation of the positively charged Zn²⁺ solvation shell in outer Helmholtz layer (OHL) and additive-involved and H₂O/anion-less solvation shell in inner Helmholtz layer (IHL). This synergistic configuration enables an organic-inorganic hybrid interface that simultaneously suppresses hydrogen evolution, accelerates desolvation, offers pH buffering capacity, and regulates Zn²⁺ deposition orientation. Zn anodes deliver high coulombic efficiency of 99.65%, long-lifespan over 6500 h, and stable operation under low temperature of -20 °C and high DOD of 85.4%. Furthermore, under practical condition of high mass loading (27 mg cm^-2) and limited N/P ratio of 3.5, Zn||VO₂ battery delivers a superhigh surface capacity of 8.1 mAh·cm^-2 and remains stable over 800 cycles, and pouch batteries can stably operate for almost 500 cycles.