▎ 摘　　要

In this work, a combined strategy of in-situ growth and sonication is proposed to prepare the reduced graphene oxide/TiO2/Ti3C2F2 (rGO/TiO2/Ti3C2F2) nanoflakes for enhanced sodium-ion batteries (SIBs). The rGO/TiO2/ Ti3C2F2 nanoflakes with the thickness of 3.806 nm exhibits the tandem nanostructure, which benefits to alleviate the aggregation of rGO and TiO2/Ti3C2F2 layers, restrict the volume expansion of TiO2 and improve the conductivity of whole electrode. Remarkably, the density functional calculation proves that the Na+ migration barrier of rGO/TiO2/Ti3C2F2 can be greatly decreased by introducing rGO. Moreover, the low charge transfer resistance is associated with rGO/TiO2/Ti3C2F2 as well, these of which enable to boost the specific capacitance. As a result, the specific capacity of rGO/TiO2/Ti3C2F2 anode reaches to 175.9 mAh g(-1) after 100 cycles at 0.1 A g(-1), which is almost twice higher than that of pure Ti3C2F2 (94.6 mAh g(-1)). Further, the rGO/TiO2/ Ti3C2F2 electrode demonstrates superior cyclic stability after 200 cycles at 1 A g(-1). The kinetics analysis features that the capacitive contribution increases to 78.6%. Beyond that, the Na+ diffusion coefficient of rGO/ TiO2/Ti3C2F2 is 4.47 x 10(-11) similar to 6.87 x 10(-10) cm(2) s(-1), which is higher than that of TiO2/Ti3C2F2 (2.12 x 10(-12) similar to 4.16 x 10(-11) cm(2) s(-1)).