Enhanced Rate Capability by Employing Carbon Nanotube-Loaded Electrospun Si/C Composite Nanofibers As Binder-Free Anodes

Si/C and Si/carbon nanotube (CNT)/C composite nanofibers were prepared by electrospinning and carbonization. The carbon nanofiber matrix can accommodate the volume change of Si nanoparticles and provide continuous pathways for efficient charge transport along the fiber axis. CNTs can improve the electronic conductivity and electrochemical performance of the composite nanofiber anodes. Results showed that many different types of connections between CNTs, Si nanoparticles and carbon matrix were formed. At a high current density of 300 mA g−1, after 30 cycles, the capacity of Si/CNT/C composite nanofiber anode was 44.3% higher than the anode without CNT and the C-rate performance of Si/CNT/C composite nanofiber anode was also superior to that of Si/C anode. It is, therefore, demonstrated that Si/CNT/C nanofibers are promising anode material with large capacities, good cycling stability, and good rate capability.