NH2–SiO2@Ti3C2Tx Core–Shell Nanostructures as Anode Materials for Li-Ion Batteries

Abstract

In this study, NH₂–SiO₂@Ti₃C₂T_x core–shell microspheres with different Ti₃C₂T_x contents are prepared by coating Ti₃C₂T_x nanosheets on the surfaces of SiO₂ microspheres using an electrostatic self-assembly method. The structures, elemental compositions, and microscopic morphologies of NH₂–SiO₂@Ti₃C₂T_x microspheres are investigated by X-Ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, and X-Ray photoelectron spectroscopy. The results show that Ti₃C₂T_x nanosheets are uniformly coated on the surfaces of the SiO₂ microspheres, and the surfaces of the SiO₂ microspheres are modified by NH₂. The maximum specific surface area of NH₂–SiO₂@Ti₃C₂T_x composite doped with 15 wt% Ti₃C₂T_x is 29.937 m² g⁻¹, with an average pore size of 0.11848 cm³ g⁻¹. The electrochemical performance test results show that after 100 cycles at a C rate of 0.2C, the specific capacity of the NH₂–SiO₂@Ti₃C₂T_x anode material increases by 270.1% compared to that of SiO₂, reaching 142.5 mAh g⁻¹. Compared with SiO₂, the NH₂–SiO₂@Ti₃C₂T_x materials have higher electrical conductivities and Li ion diffusion rates, thereby improving their rate performances, and the discharge specific capacities and cycling stability are superior to those of the SiO₂ anode material.