Facile synthesis of graphene-silicon nanocomposites with an advanced binder for high-performance lithium-ion battery anodes

In this work, the nanocomposite of silicon nanoparticles dispersed on conducting graphene (Si/graphene) was successfully synthesized using high-energy ball milling followed by thermal treatment, and Xanthan gum was developed for the first time as a novel advanced binder for Si-based lithium-ion battery anodes. Compared to the pristine Si anode, the Si/graphene composite anode showed an enhanced reversible capacity, excellent cyclic performance and rate capability, highlighting the advantages of dispersing Si nanoparticles on graphene sheets. The significant enhancement on electrochemical performance could be ascribed to the fact that the Si/graphene composite anode could maintain excellent electronic contact and accommodate the large volume change of Si during the lithiation/delithiation process. In addition, the Si/graphene anode with the gum binder exhibited improved cycling and rate performances compared to that with the conventional carboxymethyl cellulose (CMC) binder. Such an enhancement was ascribed to the high binder stiffness and the strong adhesion of the binder to Si-based particles due to the binder's specific chemical structure and properties, which helps maintain the integrity of the electrode and accommodate the volume change of Si. This work demonstrates that the Si/graphene nanocomposite with an advanced binder offers great advantages to enhance the lithium storage capacity, cyclic stability, and rate capability, making it a promising candidate as an anode material for high-performance lithium ion batteries (LIBs). (C) 2013 Elsevier B.V. All rights reserved.