Synergistic Engineering of Defects and Heterostructures Enhance Lithium/Sodium Storage Properties of F‐SnO2‐x‐SnS2‐x Nanocrystals Supported on N,S‐Graphene

Abstract Phase engineering of the electrode materials in terms of designing heterostructures, introducing heteroatom and defects, improves great prospects in accelerating the charge storage kinetics during the repeated Li + /Na + insertion/deintercalation. Herein, a new design of Li/Na‐ion battery anodes through phase regulating is reported consisting of F‐doped SnO 2 ‐SnS 2 heterostructure nanocrystals with oxygen/sulfur vacancies (V O /V S ) anchored on a 2D sulfur/nitrogen‐doped reduced graphene oxide matrix (F‐SnO 2‐x ‐SnS 2‐x @N/S‐RGO). Consequently, the F‐SnO 2‐x ‐SnS 2‐x @N/S‐RGO anode demonstrates superb high reversible capacity and long‐term cycling stability. Moreover, it exhibits excellent great rate capability with 589 mAh g −1 for Li + and 296 mAh g −1 at 5 A g −1 for Na + . The enhanced Li/Na storage properties of the nanocomposites are not only attributed to the increase in conductivity caused by V O /V S and F doping (confirmed by DFT calculations) to accelerate their charge‐transfer kinetics but also the increased interaction between F‐SnO 2‐x ‐SnS 2‐x and Li/Na through heterostructure. Meanwhile, the hierarchical F‐SnO 2‐x ‐SnS 2‐x @N/S‐RGO network structure enables fast infiltration of electrolyte and improves electron/ion transportation in the electrode, and the corrosion resistance of F doping contributes to prolonged cycle stability.