Lychee-like TiO@FeO Core-Shell Nanostructures with Improved Lithium Storage Properties As Anode Materials for Lithium-Ion Batteries

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