Synergistic Supramolecular-Cosolvent Electrolyte Engineering for Multiscale Regulation of Stable Zinc Anodes

Simultaneously achieving uniform zinc deposition and stable interfaces remains a critical challenge for aqueous zinc metal batteries. Herein, we present a synergistic electrolyte design integrating β-cyclodextrin (β-CD) as a supramolecular regulator with trimethyl phosphate (TMP) as a bulk cosolvent to enable multiscale regulation from the electrode interface to the electrolyte bulk. The β-CD additive dynamically adsorbs on the Zn surface, guiding homogeneous Zn²⁺ flux and fostering a robust solid electrolyte interphase. Concurrently, TMP reconstructs the primary solvation shell of Zn²⁺ and disrupts the hydrogen-bond network, effectively suppressing hydrogen evolution and corrosion. Spectroscopic and electrochemical analyses confirm that this cooperative mechanism optimizes both interfacial kinetics and bulk electrolyte stability. Consequently, Zn||Zn symmetric cells achieve outstanding cycling stability over 2000 h, and Zn||Cu asymmetric cells maintain a high Coulombic efficiency of 99.52% for over 1100 cycles. Full cells paired with NH₄V₄O₁₀ cathodes further demonstrate superior capacity retention and reduced self-discharge. This work provides a novel electrolyte design paradigm through molecular co-regulation, offering a general strategy for stabilizing metal anodes in aqueous batteries.