Facile silicon/graphene composite synthesis method for application in lithium-ion batteries

Lithium-ion batteries (LIBs) with silicon anodes have higher charge-discharge capacities than those with graphite anodes; however, the repeatabilities of their charge-discharge cycles are extremely low. Recently, silicon/graphene composites have been used in LIBs, but their complex synthesis inhibits the industrial applications of such LIBs. In this study, silicon/graphene composites were synthesized via a simple, environmentally friendly method using tetraethyl orthosilicate and natural graphite as inexpensive starting materials. The resulting composites were investigated using Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis, which confirmed similar silicon/carbon atomic ratios in the composites and starting materials. When these composites served as an LIB anode material, the manufactured batteries showed charge-discharge capacities and charge-discharge cycle characteristics superior to those of graphene-anode-based and siliconanode-based batteries, respectively. They also showed performances comparable or superior to those of LIBs fabricated by costly, complicated conventional methods.