Wrinkled-graphene wrapped silicon nanoparticles synthesized through charged colloidal assembly for enhanced battery performance

Elastic composite of wrinkled graphene sheets and Si nanoparticles has been prepared through engineering charged Si nanoparticles capping with 3-aminopropyl triethoxysilane and graphene oxide in colloidal state. In the composite, the Si nanoparticles are uniformly wrapped by the graphene sheets. When used as an anode for lithium-ion batteries, the as-obtained material exhibits high Coulombic efficiency, good cycling stability of 1044 mAh g(-1) at a current density of 200 mA g(-1) after 100 cycles, and superior rate capability. Such excellent electrochemical performance should be attributed to the wrinkled graphene sheets, which not only buffer volume expansion of Si nanoparticles during the cycling but also act as electrical conducting pathway.