The sluggish layered structural sodium reaction kinetics and the easy restacking property are major obstacles hindering the practical application of MoS 2 -based electrodes for sodium storage. Herein, covalently assembled two-phase MoS 2 −SnS supported by a hierarchical graphitic carbon nitride/graphene (MoS 2 −SnS@g-C 3 N 4 /G) composite is constructed to improve cycling cyclability and rate performances for Na storage. The multiphase MoS 2 −SnS@g-C 3 N 4 /G is featured with a covalent assembly strategy and an interconnected network architecture. This unique structural design can not only enhance the conductivity and facilitate fast interfacial electron transport, which is confirmed by experiments and density functional theory, but also buffer the volumetric changes of MoS 2 −SnS. As a result, the as-obtained MoS 2 −SnS@g-C 3 N 4 /G anode delivers a high reversible capacity of 834 mA h g −1 at 0.1 A g −1 , a high rate capability of 452 mA h g −1 at 5 A g −1 , and a long-term cycling stability (320 mA h g −1 at 2 A g −1 with 54.7% retention after 500 cycles) for the Na half-cell. Coupling with activated carbon (AC), our MoS 2 −SnS@g-C 3 N 4 /G|| AC sodium-ion hybrid capacitor delivers high energy/power densities (193.1 W h kg −1 /90 W kg −1 and 41.5 W h kg −1 /18,000 W kg −1 ) and a stable cycle life in the potential range of 0−4.0 V.

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 Fdoped SnO 2 -SnS 2 heterostructure nanocrystals with oxygen/ sulfur vacancies (V O /V S ) anchored on a 2D sulfur/nitrogendoped 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 À 1 for Li + and 296 mAh g À 1 at 5 A g À 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.

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