Surficial Structure Regulation of Siox Material by High-Energy Ball Milling and Wet-Alkali Chemical Reaction for Lithium-Ion Batteries

Abstract

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

Keywords: lithium-ion batteries, SiOx anode, high-energy ball-milling, ordering of amorphous silicon, surface O/Si ratio, Electrochemical performance