Comparison between SnSb-C and Sn-C composites as anode materials for lithium-ion batteries

SnSb-C and Sn-C composites have been fabricated by thermal annealing of the SnO2-Sb2O3 and SnO2 nanocomposite precursors under a C2H2-pyrolysis reducing atmosphere, respectively. Both of the as-formed SnSb intermetallic compounds and Sn particles are uniformly dispersed in the synchronously formed continuous amorphous carbon matrix. As the anode for lithium-ion batteries, the SnSb-C composite shows a high reversible capacity of 672.2 mA h g-1 after 120 cycles at a current density of 100 mA g-1 together with a rate performance of 468.8 mA h g-1 at 500 mA g-1, which are much better than those of the corresponding Sn-C composite (with similar carbon content to the SnSb-C composite; 432.1 mA h g-1 after 120 cycles at 100 mA g-1 and 331.9 mA h g-1 at 500 mA g-1). The better reversible capacity and cyclic performance of the SnSb-C composite can be attributed to the synergistic effect and strong affinity between electrochemical Sn and Sb phases as well as the synchronously formed continuous amorphous carbon matrix