Facile preparation of void-buffered Si@TiO2/C microspheres for high-capacity lithium ion battery anodes

The well-constructed Si nanostructure anode is essential for achieving high performance lithium-ion battery. In this report, void-buffered Si@TiO2/C microspheres are fabricated via a facile solid-liquid adsorption template technology followed by calcination process. Here, for the first time, the green and low-cost TiCl4 solution is employed as the inorganic titanium precursor for synthesis of size-controllable TiO2 shell. The void buffer can be controlled by the annealing temperature and concentration of the precursor of template. The Si@TiO2/C combines the merits of controllable void for releasing the mechanical stress, robust TiO2/C shell for building stable SEI film, high electronic conductivity for improving charge transfer. This specific structure is demonstrated to be effective in alleviating the volume effect during cycling process. When Si@TiO2/C microspheres are evaluated as anode of lithium-ion battery, a high reversible specific capacity of 1384 mA h g−1 is obtained after 100 cycles at 200 mA g−1. Even at a high current density of 500 mA g−1, a reversible capacity of 1038 mA h g−1 can still be retained after 400 cycles. The high-capacity electrochemical performance and easy preparation methods demonstrate the Si@TiO2/C microspheres are considered as a very promising anode material for next-generation lithium-ion batteries.