Layer-by-layer design of Si–C/CNT anodes for stable long-term cycling in lithium-ion batteries

To explore the application of silicon in lithium-ion battery anodes, silicon/carbon nanotube (Si/CNT) composites were designed, and their electrochemical performance was evaluated. Using silane and acetylene gases, Si/CNT composites with various structural configurations were synthesized via a chemical vapor deposition (CVD) process. Alternating the deposition of silane and acetylene enabled the formation of uniformly and densely distributed Si and C layers. Moreover, the structures of Si and C significantly influenced the electrochemical properties of the Si-based anodes. Particularly, the thickness of the intermediate C layers had a dominant effect on the initial Coulombic efficiency, rate capability, and cycling stability. Thus, the multilayered structure contributed to the enhanced performance of lithium-ion batteries by buffering the volume expansion of Si and providing effective pathways for electron and ion transport.