In order to improve the initial coulombic efficiency (ICE) and cycle performance of SiO, in this study, the disproportionation reaction of commercial SiO is performed with the assistance of Na₂CO₃ under high temperatures. A polydopamine-based carbon is then in situ formed on the surface of the mixture (d-SiO-G) of disproportionated-SiO and graphite. It is found that an appropriate amount of Na₂CO₃ can effectively enhance the ICE of the commercial SiO due to the formation of Si, SiO₂, and silicate; the mass ratio of d-SiO-G to the dopamine monomer is the important factor in influencing the cycling stability of the d-SiO-G@C composite. Due to the synergistic effect of graphite and the polydopamine-based carbon layer, the ICE for the d-SiO-G@C composite is 72.6%, and its capacity retention reaches 86.2% after 300 cycles, which is 11% higher than that of d-SiO-G. The modification method is an effective strategy for SiO materials in commercial applications.