Preparation and characterization of Sb-active carbons composite as negative electrode for Li-ion batteries

Sb-active carbon composite was prepared by carbothermal reduction from Sb₂O₃ and active carbon. The so-prepared material was characterized by XRD and SEM. Electrochemical lithium insertion/extraction characteristics of the material were determined by constant current charge-discharge and cyclic voltammetry methods. The results show that Sb₂O₃ is reduced to metallic Sb. More homogeneous composite can be obtained by increasing the molar ratio of reductant in raw materials. The Sb-active carbon composite heated for 12 h with a molar ratio of Sb₂O₃:C 1:4 exhibits the best electrochemical lithium insertion/extraction characteristics and possesses the initial lithium specific insertion capacity of 893 mAh/g. Even after 8 cycles, Sb-active carbon composite still shows high lithium specific extraction capacity as 548 mAh/g, which is 88% of initial lithium specific extraction capacity.