<p>Nanoparticulate Si was prepared by&#xa0;high-energy mechanical milling. A&#xa0;carbon-rich preceramic polymer was pyrolyzed at 1000 and 1200&#xa0;°C to synthesize silicon oxycarbide, which were etched with HF to prepare the oxycarbide-derived carbon. The silicon and carbon were mixed by high-energy mill to synthesize&#xa0;the Si–C nanocomposite. The charge–discharge behavior of the composite as anode in lithium half-cell configuration was found to be superior compared to either Si or carbon.&#xa0;The material showed reversible specific capacity of 1000 mAh g⁻¹&#xa0;after 200 cycles at a current density of 0.1 A g⁻¹ and 420 mAh g⁻¹&#xa0;at 2 A g⁻¹. The substantial improvement in cyclic stability and rate capability are attributed to the porous microstructure of the composite that absorbs the mechanical strain, and to the ordered carbon layers within the oxycarbide-derived carbon that improve electrical conductivity of the composite.</p> Graphical abstract <p></p>