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@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 m(2) 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.

Automated summary

In this study, lychee-like TiO2@Fe2O3 microspheres with a core-shell structure were prepared by coating Fe2O3 on the surface of TiO2 mesoporous microspheres. Experimental characterization showed that the resulting material had uniform coating, high specific surface area, and improved electrochemical performance compared to commercial graphite. The study also revealed that TiO2@Fe2O3 had higher conductivity and lithium-ion diffusion rate, leading to enhanced rate performance. The findings contribute to the identification of suitable anode materials for commercial lithium-ion batteries.