Influence of oxidation on the electrochemical properties of silicon oxide-based carbon composites for anode materials of lithium-ion batteries

•Oxidation level of SiOx can be controlled by varying the reduction conditions.•Uniform carbon layer is introduced by rotational chemical vapor deposition method.•SiC formation is suppressed using toluene in the liquid state as a carbon precursor.•Oxidation level and carbon layer thickness are systematically optimized.