Scalable synthesis of high-performance anode material SiOx/C for lithium-ion batteries by employing the Rochow reaction process

The commercial application of silicon oxide (SiOx)-based anode materials in lithium-ion batteries (LIBs) is hindered by their poor electrochemical performance and difficulty in large-scale production. Here, we report a scalable synthesis of a carbon-coated SiOx composite (SiOx/C) as an excellent and stable anode material for LIBs. By employing the industrial Rochow reaction process, metallurgic grade Si microparticles first reacted with gaseous CH3OH over a Cu-based catalyst to generate alkoxysilanes (important organosilane monomers) and SiOx particles covered with organic compounds. After separation and washing, the obtained SiOx solid particles were carbonized to generate the SiOx/C composite. The prepared SiOx/C composite used as the anode material in LIBs could deliver a high reversible capacity of 581 mAh g−1 at a higher current density of 100 mA g−1 after 100 cycles and 510 mAh g−1 after 250 cycles even at a higher current density of 500 mA g−1. It is anticipated that by employing an industrial process for alkoxysilane synthesis with controlled reaction conditions, the large-scale preparation of a SiOx/C anode material becomes highly feasible.