SiO2/C double-layer-coated SiO as a high-performance anode for lithium-ion batteries

•Micro-sized SiO@SiO2@C composite anode materials are fabricated via a liquid-phase in-situ coating approach.•The double-layer core–shell structure of SiO@SiO2@C-900 composites restricts the volume effect of silicon-based materials.•The SiO@SiO2@C-900 composites’ double-layer core–shell structure improves cycle performance.•SiO@SiO2@C-900 still has a discharge capacity of 1298.25 mAh·g−1 after 100 cycles. Silicon monoxide (SiO) has a high theoretical capacity as an anode for lithium-ion batteries, but its poor conductivity and bulk effect can cause the capacity to plummet. The combination of SiO and other materials to form a core–shell mechanism on the surface of SiO can effectively alleviate these problems. In this work, a silicon dioxide (SiO2)/carbon (C) bilayer core–shell structure coated on SiO anode material was designed and synthesized to address the issues inherent in core–shell structures. When the temperature was 900 °C, SiO@SiO2@C exhibited an excellent reversible capacity of 2500.08 mAh·g−1 and a first coulombic efficiency of 75.92 %. After 100 charge/discharge cycles, it still retained 1298.25 mAh·g−1 of its capacity. Compared with those of pure SiO, its cycling stability and capacity retention are significantly improved, providing a new approach for anode materials in lithium-ion batteries.