A Fullerene-Based Interphase Confines Interfacial Electrons for Long-Lived Zinc Metal Anodes in Aqueous Electrolytes

The intrinsic instability of the Zn/electrolyte interface, arising from dendrite growth, hydrogen evolution, corrosion, and passivation, fundamentally limits the reversibility of aqueous Zn metal anodes. Herein, we construct a fullerene-based polymer interphase (PC60) on Zn to confine interfacial electrons and regulate Zn redox chemistry. A fullerene-derived monomer integrating an electron-deficient C60 cage with polar ester and amine groups undergoes thermal polymerization to form a dense and uniform interphase. Owing to the high electron affinity and deep LUMO of C60, PC60 induces interfacial charge redistribution, yielding an electronegative passivating layer that suppresses hydrogen evolution and sulfate/polyiodide-involved corrosion, while facilitating Zn2+ desolvation and selective transport. In situ DEMS, XRD, Raman spectroscopy, and KPFM collectively reveal suppressed HER, reduced basic zinc sulfate formation, enhanced Zn2+ transference, and homogenized surface potential. Consequently, PC60/Zn enables stable cycling over 5500 h in symmetric cells, > 99.9% Coulombic efficiency for 5500 cycles in half cells, and >96% capacity retention after 1000 cycles in PC60/Zn||ZnI2 full cells. This work establishes electron confinement as an effective lever to reconstruct the interfacial electronic landscape and decouple Zn redox chemistry from parasitic reactions in aqueous Zn metal batteries.