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

Abstract

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.