In this study, we used a carbonization method to prepare biomass-based C/SiO2 composites from rice husks for use in lithium ion batteries. Carbonization was carried out at different temperatures in an N2 atmosphere and a heating rate of 5 °C min−1, and the biomass-based C/SiO2 composites were obtained. The results showed that the lithium ion batteries maintained good cycling performance under a current density of 100 mA g−1. At the same time, they had a good performance rate at different current densities. According to thermogravimetric analysis, x-ray powder diffraction patterns, Fourier transform infrared spectroscopy, Raman spectroscopy and other data for the biomass-based C/SiO2 composites, 700°C was the optimal carbonization temperature. At this temperature, some of the carbon was carbonized, and the sp2 hybridized carbon in the surface functional group was weakened. Simultaneously, the connection of sp2 hybridized carbon in C=C greatly improved the properties of the materials. According to the Brunauer–Emmett–Teller results, the biomass-based C/SiO2 composites obtained by carbonization of rice husks had micropores, which provided active sites for insertion and extraction of Li+. This method is in line with the concept of environmental protection, as carbonization is a simple process, and rice husks are by-products of processing.