VS4/carbon nanotube hybrid: A high-rate anode for sodium-ion battery

VS4 with high theoretical capacity and unique parallel quasi-one-dimensional (1D) chains structure has the potential to serve as the sodium ion battery (SIB) anode, yet the realization of its full electrochemical property is hampered by the poor electrical conductivity and sever volume expansion during cycling. To improve the conductivity and structure stability of VS4, multiwalled carbon nanotube (MWCNT) is introduced. As a result, the structure stability and charge transfer kinetics during cycling are enhanced. The synthesized VS4/MWCNT composite achieves a relatively high discharge capacity of 680 mAh g-1 at 0.2 A g-1, and excellent rate capability of 368 mAh g-1 at 5 A g-1. Characterization reveals the predominant surface control behavior of sodium storage and enhanced charge carriers' mobilities for VS4/MWCNT. Based on these results, the VS4/MWCNT composite offers vast potential as a promising anode for rechargeable SIBs.

Automated summary

The introduction of multiwalled carbon nanotube significantly improves the conductivity and structural stability of VS4, enhancing its performance in sodium ion batteries. The synthesized VS4/MWCNT composite exhibits good discharge capacity and rate capability at different current densities.