Large-Scale Production of a Silicon Nanowire/Graphite Composites Anode via the CVD Method for High-Performance Lithium-Ion Batteries

Aiming at preparing a cheap and high-performance anode material, a novel carbon-coated silicon nanowire on a surface of graphite microsphere composites was fabricated by employing a new silicon precursor via the chemical vapor deposition method. The chemical vapor deposition method could further reduce the cost and realize the large-scale preparation of silicon/graphite composites and simultaneously enhance the bonding strength between silicon and graphite. Due to the lower cost and lower requirement on equipment compared with silane, chloromethylsilane was selected to produce pure silicon as the content of carrier gas is 25 vol %. Deposited with silicon and carbon for 15 and 30 min, respectively, the carbon/silicon nanowire/graphite microsphere composites display outstanding electrochemical performance with a specific capacity of 580 mA h g–1 at a current density of 0.2 C after 100 cycles and high-rate performance of 300 mA h g–1 at 5 C. Besides, the adsorption and deposition mechanisms of silicon on a graphite surface are expounded. This new preparation process is an alternative route for promoting the practical application of silicon/graphite composites.