For several decades, silicon (Si) has been investigated as a promising alternative to conventional graphite anodes because of its high specific capacity and proper working voltage. However, the huge volume change of Si (~400%) upon (de)lithiation causes severe mechanical degradation accompanying with ceaseless side reaction, rendering the application of Si anode challenging. Although nanoengineering has made a significant leap forward for Si anodes, nanostructured Si still suffers mechanical degradation from repeated (de)alloying and eventually becomes highly porous structure which is surrounded by accumulated SEI layers after long-term cycling. Designing homogeneous nano-alloy Si anode will be a feasible way to manipulate intrinsic properties of Si anode. In this talk, as a facile but innovative approach for controlling the single-nanometer scale Si anode, our recent work regarding the micron-sized Si/carbon composite anode synthesized by impregnation of petroleum pitch into nano-porous Si will be discussed. With the preliminary impregnation of pitch into nanoporous Si, the sintering of vulnerable primary Si particles (< 4nm) is successfully prevented against indispensable heat treatment for carbonization. This micron-sized Si/carbon composite having considerable homogeneity between Si and carbon in single nanometer-scale provides practical solution to the challenge of nanostructured Si anode in single-nanometer scale, enabling very stable cycling of Si||Li(Ni0.5Co0.2Mn0.3)O2 battery with 80% capacity retention after 450 cycles.