Facile Synthesis of Core-Shell Structured SiO(2)@Carbon Composite Nanorods for High-Performance Lithium-Ion Batteries

Recently, SiO(2) has attracted wide attention in lithium-ion batteries owing to its high theoretical capacity and low cost. However, the utilization of SiO(2) is impeded by the enormous volume expansion and low electric conductivity. Although constructing SiO(2)/carbon composite can significantly enhance the electrochemical performance, the skillful preparation of the well-defined SiO(2)/carbon composite is still a remaining challenge. Here, a facile strategy of in situ coating of polydopamine is applied to synthesis of a series of core-shell structured SiO(2)@carbon composite nanorods with different thicknesses of carbon shells. The carbon shell uniformly coated on the surface of SiO(2) nanorods significantly suppresses the volume expansion to some extent, as well as improves the electric conductivity of SiO(2). Therefore, the composite nanorods exhibit a remarkable electrochemical performance as the electrode materials of lithium-ion batteries. For instance, a high and stable reversible capacity at a current density of 100 mA g(−1) reaches 690 mAh g(−1) and a capacity of 344.9 mAh g(−1) can be achieved even at the high current density of 1000 mA g(−1). In addition, excellent capacity retention reaches 95% over 100 cycles. These SiO(2)@carbon composite nanorods with decent electrochemical performances hold great potential for applications in lithium-ion batteries.