Surficial structure regulation of SiO_x material by high-energy ball milling and wet-alkali chemical reaction for lithium-ion batteries

The inhomogeneous nature of SiO_x anode material on the atomic scale directly affects its electrochemical performance. A large irreversible capacity loss at the first cycle severely hinders the applications of SiO_x materials in lithium ion batteries. The modification of SiO_x by means of high-energy ball-milling and wet alkali chemical reaction can tune the ordering of amorphous silicon and silicon dioxide in SiO_x materials, which is beneficial to the activation of nano silicon region and the surficial composition optimization of the lithiated products of SiO_x during the first discharge process, and the formed Li₂SiO₃ phase and the increased O/Si ratio in the surface of SiO_x contribute to the improved cyclic performance. This surface regulation approach is quite simple, efficient and suitable for large-scale applications of high-performance SiO_x anode material.