Kilogram-Scale Fabrication of Si/C Bean-Structured Materials as Stable Anodes for Li-Ion Storage

摘要

The practical application of Si-based materials is widely impeded by poor electrochemical cycling stability. Here, inspired by the compact cladding and close connection structure of beans, an efficient buffering bean-structured material of Si/C framework as a stable anode for Li-ion storage is designed. By a simple ball-milling process, the kilogram-scale production of the Si/C can be realized. The Si/C composites exhibit excellent enhancement of electrochemical performance with a large storage capacity (1162.2 mAh g(-1) at 0.1 C and 920.6 mAh g(-1) at 0.2 C) and superior cycling stability (734 mAh g(-1) after 200 cycles). The superior electrochemical performance is from the unique bean-structured Si/C composites. Some micropores in porous carbon (PC) materials can offer void space that can alleviate stress and reduce volume expansion during the lithiation/delithiation process, and the PC can also act as a conductive matrix to enhance the conductivity and facilitate the diffusion of Li ions and electrons.