Enhancing Zinc Anode Reversibility through Dynamic Interface Engineering with Monolayer Hydrophobic Carbon Dots

Aqueous zinc-ion batteries promise low-cost and safe grid storage, but their practical application is hindered by poor Zn anode reversibility, primarily due to dendrite formation and water-induced side reactions in the electric double layer (EDL) structure. Herein, a monolayer of hydrophobic carbon dots (CDs) was dynamically constructed at the electrode/electrolyte interface. The trace-added hydrophobic CDs in the electrolyte reconstruct a hydrophobic and favorable EDL structure, suppressing water-induced side reactions in the inner Helmholtz layer and facilitating the desolvation of hydrated zinc ions at the outer Helmholtz layer. Furthermore, the hydrophobic CD monolayer maintained dynamic interfacial integrity during Zn²⁺ plating. Consequently, the lifespans of the Zn symmetric cells were extended to 2400 h at 10 mA cm^-2 and 600 h at 30 mA cm^-2. Both coin-type and pouch-type full cells with an area of 90 cm² showed exceptional stability. This concept of a dynamic monolayer protective interface presents an appealing avenue for reversible metal anodes.