Silicon Carbon Nanoparticles Coated with Reduced Graphene Oxide with High Specific Capacity and High-Rate Performance as Anode Material for Lithium-Ion Battery

Abstract

Silicon carbon nanoparticles (SCNPs) coated with reduced graphene oxide (rGO) were fabricated by a hydrothermal method and subsequently by a simple heat treatment process. SCNPs/rGO exhibit excellent electrochemical performance which not only attributes the rGO layer to inhibit the volumetric expansion of silicon and reduce the impedance between the active material and lithium ions during the electrochemical process, but also improves the electrical conductivity of SCNPs/rGO. The as-prepared compound was cyclically tested at a current density of 150[Formula: see text]mA/g, with the first charge and discharge capacities of 3152.2[Formula: see text]mAh/g and 3342.7[Formula: see text]mAh/g, respectively. Moreover, the electrochemical performance of SCNPs/rGO was better than SCNPs. The [Formula: see text] values for fresh battery, after 1 cycle and 100 cycles, are 120.9[Formula: see text][Formula: see text], 120.5[Formula: see text][Formula: see text] and 104[Formula: see text][Formula: see text]. Thus, compared with SCNPs, SCNPs/rGO exhibited lower overall impedance values. These results indicate that the addition of graphene layer significantly improved the electrochemical performance of SCNPs electrodes and reduced the internal resistance of the battery.