▎ 摘　　要

Nanostructure engineering of the active materials including decreasing the material feature size, or designing appropriate heterostructures, offers immense promise in improving the charge storage kinetics, and enhancing the practical performance in this work, we report a new synthesis of SnO2@SnS2 heterostructured quantum dots (HQDs) uniformly anchored on N-doped graphene (SnO2@SnS2@NG), promoted by the electrostatic interaction between NG and Sn4+. The faster electron transport kinetics than SnO2 and SnS2 can be achieved at heterointerfaces of SnO2@SnS2 through DFT calculation analysis. And, the SnO2@SnS2 HQDs (3-5 nm) can shorten Li/Na ion diffusion pathway greatly, while the NG substrate can provide excellent electrical conductivity and good structural stability. As a result, the ion diffusion coefficient of this HQDs structure is 60 folds higher than that of bare SnO2@SnS2 nanoparticle. High reversible charge storage capacities are achieved for both LIBs (1081 mA h g(-1) at 0.05 A g(-1), 343 mA h g(-1) at 5 A g(-1)) and SIBs (450 mA h g(-1) at 0.05 A g(-1), 75 mAhg(-1) at 5 Ag-1).