Facile approach to SiOx/Si/C composite anode material from bulk SiO for lithium ion batteries

Abstract

The m-SiO_x/Si composite for lithium ion battery anode was prepared via a partial reduction reaction between ball-milled silicon monoxide and magnesium by high-energy mechanical milling. The m-SiO_x/Si is composed of Si-suboxide and embedded Si nano-crystallites. The particles were further covered by a uniform carbon layer on the surface via a chemical vapor deposition process. The m-SiO_x/Si/C composite shows a stable reversible capacity of ca. 1250 mA h g⁻¹ and excellent cycling stability with 90.9% capacity retention on the 100th cycle versus the 6th one (compared at the same current rate). In contrast, SiO pre-milled for 25 h presents a reversible capacity of only ca. 900 mA h g⁻¹ under the same carbon coating condition.