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

Abstract

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 silicon-anode-based batteries, respectively. They also showed performances comparable or superior to those of LIBs fabricated by costly, complicated conventional methods. • Ecofriendly method to synthesize silicon–graphene composites for LIB anodes. • Inexpensive starting materials (TEOS and GO) reduce overall production costs. • Obtained composites outperform both graphite and silicon anodes. • Performance comparable to that of more expensive, less ecofriendly composites.