A straightforward approach towards Si@C/graphene nanocomposite and its superior lithium storage performance

The carbon-coated Si nanoparticle/graphene composite (Si@C/G) was prepared through a thermal annealing of the freeze-dried mixture of Si nanoparticles, sucrose, and graphene oxide. This straightforward approach realizes the carbon coating of Si nanoparticles and the good dispersion of graphene sheets in Si@C nanoparticles simultaneously. As an anode material for lithium-ion batteries, the Si@C/G exhibits high Coulombic efficiency, good cycling stability of 1410 mAh g−1 at a current density of 500 mA g−1 after 100 cycles, and superior rate capability. Such excellent electrochemical performance could be attributed to the combined work of carbon shells and electrically conductive graphene networks. This study proposes a strategy for other electrode materials with huge volume changes and low electrical conductivity to improve the lithium storage performance.