Facile preparation and electrochemical properties of amorphous SiO_2/C composite as anode material for lithium ion batteries

摘要

An amorphous SiO_2/C composite anode material is synthesized via a sol-gel route combining with mechanical milling and post heat-treatment processes. The synthesized amorphous SiO_2/C composite presents a nanostructure composing of amorphous SiO_2 cluster and coating carbon layer. The amorphous SiO_2/C electrode exhibits high reversible capacity (～600 mA h g~(-1)), stable cycling performance and excellent rate-capability. Mechanical milling causes SiO_2/C composite amorphization which makes the active material possess good electrochemical activity. The coating carbon layer can not only increase electronic conductivity, but also accommodate part of the volume expansion occurred during discharge/ charge process.