Fabrication of SiO@Graphite@C@Al2O3 as Anode Material for Lithium-Ion Batteries.

In this study, SiO@graphite@C@Al₂O₃ (SiO@G@C@A) composites are synthesized by varying the content of Al₂O₃, and their morphology and structure and their electrochemical performance are investigated in detail. The results indicate that the SiO/G@C@A-2 composite exhibits a specific capacity of 977.1 mA h g⁻¹ at a current density of 0.1 A g⁻¹ with a coulombic efficiency of 71.15%. Even after 100 cycles at a current density of 0.5 A g⁻¹, it retains a delithiated specific capacity of 640.7 mA h g⁻¹ and a capacity retention rate of 73.56%. Moreover, when the current density is raised to 2 A g⁻¹, it maintains a delithiated capacity of 568.4 mA h g⁻¹ and a capacity retention rate of 58.51%. The excellent electrochemical performance is ascribed to the synergistic effect of different components. The inclusion of graphite enhances overall conductivity while mitigating the volume expansion of the SiO. The application of asphalt pyrolytic carbon as a coating effectively isolates the SiO from the electrolyte, further reducing volume expansion and enhancing conductivity. The introduction of Al₂O₃ can absorb trace amounts of hydrogen fluoride (HF) generated during charge and discharge processes. Additionally, it facilitates the formation of an AlF₃ film on the particle surfaces, which hinders and decelerates electrolyte dissolution into the electrode. The prepared composites exhibit promising prospects as lithium-ion battery anode materials. [ABSTRACT FROM AUTHOR]