Facile synthesis of carbon-coated SiO/Cu composite as superior anode for lithium-ion batteries

Carbon-coated SiO/Cu composites are facilely prepared via Cu deposition combined with carbon coating on SiO nanoparticles. Transmission and scanning electron microscopic images reveal that the composites exhibit microstructures comprising amorphous carbon shell and Cu-deposited SiO core with sizes ranging from 100 to 200 nm. The electrochemical test results indicate that the initial reversible specific capacity of the as-prepared anodes reach up 1140 mAh g−1 at a current density of 100 mA g−1, combined with an excellent cycling performance with capacity retention of 88.3% over 150 cycles and a good rate-capability. The deposited Cu particles disperse along the surfaces of SiO nanoparticles, providing an efficient electron pathway from the current collector to most of the surface area of the active material. Meanwhile, the carbon layer plays a role in keeping the holistic electric conductivity and acts as soft media to accommodate part of the significant volume change of the active materials. The synergistic effect of deposited Cu and amorphous carbon layer encourage the composites to maintain good conductive network and structural integrity during cycling. This, in turn, results in excellent electrochemical performances.