▎ 摘　　要

Cost-effective, safe, and highly performing energy storage devices require rechargeable batteries, and among various options, aqueous zinc-ion batteries (ZIBs) have shown high promise in this regard. As a cathode material for the aqueous ZIBs, manganese dioxide (MnO2) has been found to be promising, but certain drawbacks of this cathode material are slow charge-transfer capability and poor cycling performance. Herein, a novel design of graphene quantum dots (GQDs) integrated with Zn-intercalated MnO2 nanosheets is put forward to construct a 3D nanoflower-like GQDs@ZnxMnO2 composite cathode for aqueous ZIBs. The synergistic coupling of GQDs modification with Zn intercalation provides abundant active sites and conductive medium to facilitate the ion/electron transmission, as well as ensure the GQDs@ZnxMnO2 composite cathode with enhanced charge-transfer capability and high electrochemical reversibility, which are elucidated by experiment results and in-situ Raman investigation. These impressive properties endow the GQDs@ZnxMnO2 composite cathode with superior aqueous Zn2+ storage capacity (similar to 403.6 mAh center dot g(-1)), excellent electrochemical kinetics, and good structural stability. For actual applications, the fabricated aqueous ZIBs can deliver a substantial energy density (226.8 W center dot h center dot kg(-1)), a remarkable power density (650 W center dot kg(-1)), and long-term cycle performance, further stimulating their potential application as efficient electrochemical storage devices for various energy-related fields.