SiOx-based electrodes have shown great potential as lithium ion battery anodes because of their high specific capacity. Nonetheless, synthesis of SiOx-based anodes in an industrially adaptable scale still remains as a great challenge. Herein, we adopt a highly efficient colloidal route to enable scalable and high yield synthesis of core-shell SiOx/C composite. The prepared SiOx/C composite presents a well-distributed nanostructure composing of SiOx nanoparticles coated with a thinner carbon layer. The electrode delivers a stable reversible capacity of ca. 820 mAh g−1 over 100 cycles, and exhibits excellent rate capability. The nano-scale feature of SiOx and the coating carbon layer ensure the excellent electrochemical performance of SiOx/C. The approach is facile, mild and mass-productive, which can be adopted for tunable large-scale production of high-capacity SiOx/C composite anode.