Graphene Aerogel-Supported Silicon@Carbon Hybrids with Double Buffering Structure as Anode for Lithium-Ion Battery
Graphene aerogel-supported silicon@carbon (SCG) hybrids with a double buffering structure were prepared via self-assembly and a solvothermal method. Nano-silicon (Si) particles coated with amorphous carbon were uniformly distributed on the surface of graphene. The amorphous carbon transformed from chitosan acted as a bridge to connect Si particles with graphene. The hierarchical structure of the resulting hybrids with multipores not only provided secondary cushions for the expansion of active Si during the charge/discharge process but also created fast access channels for the transmission of Li+. The SCG hybrid exhibited an excellent initial charge capacity of 1298.6 mAh g−1 and remained at 899.6 mAh g−1 after 100 cycles at 200 mA g−1. It also showed a remaining capacity of 737.6 mAh g−1 at 500 mA g−1 after 200 cycles. The capacity could reach up to 551.1 mAh g−1 at a high current density of 2000 mA g−1. These results suggest that the double buffer and porous structure can solve the problem of volume expansion of Si in Si-based hybrids, thus rendering them suitable for various applications.