In recent years, silica (SiO2) has been regarded as a promising anode material for the lithium ion batteries (LIBs) due to its
low discharge potential, high theoretical specific capacity, and abundant in nature. However, some intrinsic characteristics,
such as the poor electrical conductivity, large volume variation during the repeated charge-discharge process and strong
crystalline Si-O bond, to a large extent hinder the practical application of SiO2. Therefore, developing a strategy, which is easily controllable, low-cost, nontoxic and highly productive, to enhance the lithium storage performance of SiO2/C composites is necessary. In this work, we prepared the SiO2/C nanocomposites through a simple and low-cost heat treatment process. When the as-obtained nanocomposites were used as anodes for the lithium ion batteries, they exhibited a high specific capacity of 660 mA h g-1 at 100 mA g-1 after 200 cycles. In addition, a good rate capability was also achieved through the heat treatment.
The improved electrochemical performance of the SiO2/C nanocomposites is mainly ascribed to the increment of crystalline
interplanar spacing and the increased defects in the carbon-coated structure, which is beneficial to embed a larger number of lithium-ions.