Preparation and electrochemical performance of CoSb alloy anode material for Li-ion batteries

Micro-sized CoSb alloy powders were synthesized by carbothermal reduction method from oxides of Co and Sb. The thermodynamic feasibility was calculated and the kinetic process was examined by DTA and XRD. Sb is firstly reduced from Sb2O3, followed by the reduction of Co from Co3O4 and the alloying of Sb with Co. The liquid feature of Sb at synthesis temperature renders the CoSb particles with a worm-like shape. Compared with nano-sized CoSbx composites, the synthesized CoSb anode with micro-sized particles exhibits lower initial irreversible capacities, mainly ascribed to the lower specific surface area and the higher chemical stability of so-obtained CoSb powders. CoSb electrode shows a high specific capacity (365 mAh/g or 2923 mAh/cm(3) after 35 cycles), good cycling stability and rate-capability, representing a promising anode material for Li-ion batteries. (C) 2009 Elsevier B.V. All rights reserved.