Glycine/Carbon Quantum Dots Dual Modulation Cooperatively Stabilizing Zn Anode Interfaces

Abstract

Aqueous zinc-ion battery systems (AZIBs) demonstrate significant potential for grid-scale energy storage applications. Nevertheless, the limited electrochemical durability of zinc electrodes, primarily due to parasitic reactions in aqueous electrolytes and uncontrolled dendrite formation, poses substantial challenges. In this work, double-effect glycine (Gly)/carbon quantum dots (CQDs) hybrid additives were explored to realize electrochemically stable Zn anode with high reversibility. Gly can regulate Zn2+ solvation sheath reconstruction, whereas hydrophilic nanocrystalline CQDs improves the kinetics of Zn2+ plating/stripping and provides the preferential nucleation domains for epitaxial zinc electrodeposition. Due to this dual effect, Zn//Zn symmetric cells demonstrate unprecedented electrochemical robustness, sustaining stable cycling over 2000 h (83 days) under demanding operational conditions (1 mA cm-2, 1 mAh cm-2) while exhibiting remarkable rate capability. Zn//Cu asymmetric cells demonstrate exceptionally average Coulombic efficiency (CE) of 99.02% under standard plating conditions (1 mA cm-2, 0.5 mAh cm-2).