Facile fabrication of Si/Sb/Sb2O3/G@C composite electrodes for high-performance Li-ion batteries†
A silicon/antimony/antimony oxide/graphite@amouphous carbon (Si/Sb/Sb2O3/G@C) composite material was prepared successfully via a simple ball milling and high temperature calcination process. Its structural characterization showed that Si and Sb/Sb2O3 were dispersed into the graphite layer and coated with amorphous carbon. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results revealed that Sb2O3 was partly reduced to Sb by carbon, which could improve its electronic conductivity. Besides, Si, Sb, Sb2O3 and carbon have different lithiation/delithiation voltage plateaus, which can act as a mutually buffering matrix, thus improving its electrochemical performance. Due to the high specific capacity, good electronic conductivity and stable cycling performance benefited from the Si/Sb/Sb2O3, Sb/G and G/C, respectively, as well as the mutually buffering matrix of all the active materials, the resulting composite electrode materials exhibit excellent electrochemical performance. The composite material exhibited good cycling performance (a stable reversible delithiation capacity of 567.8 mA h g−1 after 180 cycles), excellent rate capability (∼360 mA h g−1 and 280 mA h g−1 at current densities of 1000 mA g−1 and 2000 mA g−1, respectively) and decreased polarization resistance. This work demonstrates a facile and cost-effective approach to preparing composite materials with complementary advantages for use in high-performance Li-ion batteries.