Antimony-Coated SiC Nanoparticles as Stable and High-Capacity Anode Materials for Li-Ion Batteries

A simple synthetic route was developed to transform micrometer-sized Sb powders into new Sb-sandwiched nanocomposite particles (SiC-Sb-C) with Sb nanoparticles pinned on rigid SiC nanocores and surface-coated with carbon by use of a high-energy mechanical milling technique at ambient temperature. The as-prepared SiC-Sb-C nanoparticles exhibited excellent cycling ability and rate capability, delivering a specific capacity of >440 mA.h g(-1) after 120 cycles and a quite high capacity of >= 220 mA.h g(-1) at a very high-rate of 4 C (2000 mA g(-1)). This greatly improved electrochemical performance could be attributed to the structural stability of this material, which can not only effectively confine the volume expansion of the sandwiched Sb layer but also prevent the aggregation of Sb nanocrystallites and keep the mechanical integrity of the electrodes. In addition, this new synthetic method is completely green with a full utilization of raw materials and without any emission of wastes, easily adopted for large-scale production and also extended for other attractive lithium storage metals and alloys.