Multilayer Silicon−Carbon-Coated Graphite as an Anode Material for a Lithium Ion Battery

To address the volume expansion effect and poor electronic conductivity of silicon-based anode materials during the lithium insertion and extraction process, different graphite−silicon−amorphous carbon composite materials were prepared by chemical vapor deposition and carbon coating methods. Comparing single-layer silicon−carbon-coated graphite (GSC) with multilayer silicon−carbon-coated graphite (GSCSC), it was found that the layered silicon deposition and double-carbon-layer structure of GSCSC can effectively adapt to volume changes, and the outer carbon coating can prevent silicon from contacting the electrolyte to form a stable SEI film. Its initial discharge specific capacity reached 702.36 mAh g−1 (0.05 C), with a coulombic efficiency of 93.14%. After 280 cycles at 0.5 C, it maintained 484.24 mAh g−1 and still had a high-rate performance of 275.55 mAh g−1 at 2 C, indicating that the multilayer interlayer structure significantly improved the cycling stability and conductivity.