Facile synthesis of multi-phase (Si+SiO 2 )@C anode materials for lithium-ion batteries.

To bring about a revolution in energy storage through Li-ion batteries, it is crucial to develop a scalable preparation method for Si-based composite anodes. However, the severe volume expansion and poor ionic transport properties of Si-based composites present significant challenges. Previous research focused on SiO and nano Si/C composites to address these issues. In this study, mechanical milling was used to introduce a SiO x layer onto the surface of Si by mixing Si and SiO 2 in a 1 : 1 mass ratio. The resulting Si+SiO 2 composites (denoted as SS50) exhibited an initial coulombic efficiency (ICE) of 73.5% and high rate performance. To further stabilize the overall structure, kerosene was introduced as a carbon source precursor to generate a coating layer. The resulting multiphase composite structure (SiO x +SiO 2 +C), designated as SS50-900C, demonstrated a capacity retention of 79.5% over 280 cycles at its capacity of 487 mA h g -1 . These results suggest that a cost-effective mechanical ball milling refinement of Si+SiO 2 and a gas-phase encapsulation process can significantly improve the electrochemical performance of Si-based composites.