A stable silicon/graphene composite using solvent exchange method as anode material for lithium ion batteries

Current research has demonstrated the combination of the high theoretical capacity offered by silicon nanoparticles (Si NPs) with graphene-based matrices in order to produce a high energy density and stable lithium ion battery system. However, Si NPs do not mix well with graphene oxide aqueous suspensions and thus create severe segregation of the materials. In this letter, we propose a simple, cost-effective and commercially-viable solvent exchange process to improve the interaction of the Si NPs in poor solvent environments such as in aqueous media. Using N-methylpyrrolidone (NMP) to disperse the Si NPs and followed by a solvent exchange process, we are able to improve the dispersion and stability of Si NPs in aqueous graphene oxide aqueous suspension. Consequently, this also improves the output and the stability of the lithium ion battery using the aforementioned composite system. (C) 2013 Elsevier Ltd. All rights reserved.