Beaded structured CNTs-Fe3O4@C with low Fe3O4 content as anode materials with extra enhanced performances in lithium ion batteries

Abstract

The present paper reports a facile method to synthesize CNT-Fe₂O₃ and CNTs-Fe₃O₄@C beaded structures by deposition of Fe₂O₃ and carbon layers on CNTs, which integrate both electronic conductivity and buffering matrix design strategies. The CNT-Fe₂O₃ and CNTs-Fe₃O₄@C were tested as anode materials for lithium-ion batteries, CNT-Fe₂O₃ showed excellent cycling performance, the reversible capacity retention after 80 cycles is stable at 410 mA h g⁻¹. However, CNTs-Fe₃O₄@C exhibited improved reversible capacity and better cycling performance when compared to CNT and CNTs-Fe₂O₃. The highly improved reversible capacities are attributed to the combination of (a) the network structured CNTs, which improve the matrix electrical conductivity, (b) the mesopores created by the carbon coating on Fe₃O₄ nanoparticles and CNTs, which increases lithium-ion mobility and storage, and (c) the Fe₃O₄ nanoparticles attached to the CNTs facilitate the transport of electrons and shorten the distance for Li⁺ diffusion. This study provides a cost-effective, highly efficient method to fabricate nanomaterials which combines carbon nanotubes with iron oxide nanoparticles for the development of lithium ion batteries with high-performance.