Effect of carbonization temperature on the electrochemical performance of monodisperse Carbon/SiO₂ nanocomposites as lithium-ion batteries anode

Silicon dioxide, SiO₂, is electrochemically inactive and therefore cannot be used directly as an anode. While it has the advantages of cost-effectiveness and high cycle stability, it is necessary to improve its electrochemical activity in order to employ this material as an anode. Embedding carbon in an SiO₂ matrix is considered as an effective strategy for improving its activity. The facile sol-gel method synthesized C/SiO₂ nanocomposites have uniform distributions of carbon and silica at the molecular level. After carbonization at 800 °C, the C/SiO₂-800 °C nanocomposites exhibits both the high specific surface area of 480.38 m² g⁻¹ and enhanced conductivity. These improvements significantly enhance electrochemical activity and Li diffusivity. In particular, the C/SiO₂-800 °C anode exhibits the remarkable reversible capacity of 832.19 mAh g⁻¹ after 300 cycles at a current density of 100 mA g⁻¹. These results demonstrate that C/SiO₂-800 °C can be employed as alternative anode material for lithium-ion batteries.