Facile preparation of micron-sized silicon-graphite‑carbon composite as anode material for high-performance lithium-ion batteries

Silicon/carbon (Si/C) composites have become the mainstream anodes for silicon-based lithium-ion batteries (LIBs) with outstanding stability and high capacity, in which carbon can significantly stabilize the silicon anodes. Currently, most Si/C composites use nano‑silicon as raw materials, which suffer from low energy density, high price and preparation complexity. Here, we have developed a silicon-graphite‑carbon ternary composite (Si-G-C-15) with cheap micron-sized silicon as raw materials. It was prepared by ball-milling of micron silicon and graphite and subsequent carbonization of PAN, followed by NaOH selective etching. Electrochemical test results demonstrate that Si-G-C-15 can possess a reversible capacity of 965 mAh/g at 200 mA/g, with a capacity retention of 71.34% and 786 mAh/g at a high current density of 1 A/g after 100 cycles. Notably, this facile preparation process of silicon anodes with high rates and good capacity stability highlights the potential practical application.