Preparation and electrochemical performance of nanocarbon-isolated nano-sheet silicon lithium-ion battery anode material

In this paper, nanocarbon-isolated nano-sheet silicon(Si) electrode Si@CNT/C has been developed by pyrolysis of the compound of Si and polyaniline (PANI)/CNT nanocomposite. The results suggest that CNT content in electrode plays a decisive role in the specific capacity, rate capability, and long-term cycle stability of the battery. Si@CNT(M)/C/graphite(G) electrode with high (10.8wt%) CNT content demonstrates the specific capacity of 1201 mAh·g−1 at 100 mA·g−1 current density, which is much better than 491 mAh·g−1 for the Si@CNT(S)/C/G with low (1.3wt%) CNT content. After 500 cycles, the Si@CNT(M)/C/G electrode still remains 700 mAh·g−1 specific capacity, while the Si@CNT(S)/C/G electrode decreases to 200 mAh·g−1. This is caused by CNT conductive network in the electrode, which can maintain not only the structural stability of the Si but also the conductivity throughout the cell cycles.