Lychee-like TiO₂@Fe₂O₃ Core-Shell Nanostructures with Improved Lithium Storage Properties as Anode Materials for...

In this study, lychee-like TiO₂@Fe₂O₃ microspheres with a core-shell structure have been prepared by coating Fe₂O₃ on the surface of TiO₂ mesoporous microspheres using the homogeneous precipitation method. The structural and micromorphological characterization of TiO₂@Fe₂O₃ microspheres has been carried out using XRD, FE-SEM, and Raman, and the results show that hematite Fe₂O₃ particles (7.05% of the total mass) are uniformly coated on the surface of anatase TiO₂ microspheres, and the specific surface area of this material is 14.72 m² g^-1. The electrochemical performance test results show that after 200 cycles at 0.2 C current density, the specific capacity of TiO₂@Fe₂O₃ anode material increases by 219.3% compared with anatase TiO₂, reaching 591.5 mAh g^-1; after 500 cycles at 2 C current density, the discharge specific capacity of TiO₂@Fe₂O₃ reaches 273.1 mAh g^-1, and its discharge specific capacity, cycle stability, and multiplicity performance are superior to those of commercial graphite. In comparison with anatase TiO₂ and hematite Fe₂O₃, TiO₂@Fe₂O₃ has higher conductivity and lithium-ion diffusion rate, thereby enhancing its rate performance. The electron density of states (DOS) of TiO₂@Fe₂O₃ shows its metallic nature by DFT calculations, revealing the essential reason for the high electronic conductivity of TiO₂@Fe₂O₃. This study presents a novel strategy for identifying suitable anode materials for commercial lithium-ion batteries.