Porous carbon assisted carbon nanotubes supporting Fe3O4 nanoparticles for improved lithium storage

Abstract

Herein, to efficiently improve the lithium storage of Fe3O4 nanoparticles, a distinctive porous carbon (PC) assisted carbon nanotubes (CNTs) supporting architecture has been designed and fabricated successfully. The Fe3O4 nanoparticles are deposited on the surface of CNTs and then covered by an extra PC. In such a designed architecture, highly conductive and robust CNTs can not only improve the conductivity but also boost the structure of the as-fabricated Fe3O4-based composite (CNTs@Fe3O4@PC). In particular, the foam-like PC has a certain level of volume elasticity and open tunnel-like structure to better anchor the Fe3O4 nanoparticles on the surface of CNTs and facilitate the transfer of electrons and ions, therefore guaranteeing the fast kinetics and long-term stability. The results show that the capacitive contribution is predominant in lithium storage of the CNTs@Fe3O4@PC electrode. Consequently, the as-fabricated CNTs@Fe3O4@PC shows high capacity, good rate capability, and long life, displaying 766 and 572 mAh g-1 after 400 and 700 cycles at 200 and even 1000 mA g-1, respectively. Thus outstanding performance makes the CNTs@Fe3O4@PC have great potential to be advanced lithium-ion battery anode materials. Furthermore, this strategy can be extended to other nanostructured metal oxide anodes, such as CoO, SnO2, and Bi2O3 nanomaterials.