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

In this study, lychee-like TiO2@Fe2O3microspheres with a core-shell structure have been prepared by coating Fe2O3on the surface of TiO2mesoporous microspheres using the homogeneous precipitation method. The structural and micromorphological characterization of TiO2@Fe2O3microspheres has been carried out using XRD, FE-SEM, and Raman, and the results show that hematite Fe2O3particles (7.05% of the total mass) are uniformly coated on the surface of anatase TiO2microspheres, and the specific surface area of this material is 14.72 m2g−1. The electrochemical performance test results show that after 200 cycles at 0.2 C current density, the specific capacity of TiO2@Fe2O3anode 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@Fe2O3reaches 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 TiO2and hematite Fe2O3, TiO2@Fe2O3has higher conductivity and lithium-ion diffusion rate, thereby enhancing its rate performance. The electron density of states (DOS) of TiO2@Fe2O3shows 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.Keywords:lithium-ion batteries;anode materials;TiO2@Fe2O3microspheres;electrochemical properties;first-principles calculations