Fabrication of graphene nanoplatelets-supported SiO_x-disordered carbon composite and its application in lithium-ion batteries

Developing high-capacity electrode materials is critical to enhance the energy-density of lithium-ion batteries. Here, a new graphene nanoplatelets-supported SiO_x-disordered carbon composite (SiO_x-C/GNPs) is fabricated by a Stöber-type process and high-temperature treatment. When used as an anode for lithium-ion batteries, SiO_x-C/GNPs exhibits excellent cycle stability and rate capability even under deep charge-discharge cycling. A stable reversible capacity of about 630 mAh g^-1 (calculated on the total mass of the composite) can be achieved at a current density of 100 mA g^-1 and the capacity retention is nearly 100% after 250 cycles. Additionally, the plateau voltages of lithium extraction for the composite are only slightly higher than those for the commercial graphite, which ensures the high energy density of the assembled batteries. The superior electrochemical performance of this novel material is due to its unique features: excellent electronic conductivity, short transportation length for both lithium ions and electrons, elastomeric space to accommodate volume changes upon Li insertion/extraction and robust connection between SiO_x and GNPs. Crown