CNT@Fe₃O₄@C coaxial nanocables: One-pot, additive-free synthesis and remarkable lithium storage behavior

By using carbon nanotubes (CNTs) as a shape template and glucose as a carbon precursor and structure-directing agent, CNT@Fe₃O ₄@C porous core/sheath coaxial nanocables have been synthesized by a simple one-pot hydrothermal process. Neither a surfactant/ligand nor a CNT pretreatment is needed in the synthetic process. A possible growth mechanism governing the formation of this nanostructure is discussed. When used as an anode material of lithium-ion batteries, the CNT@Fe₃O₄@C nanocables show significantly enhanced cycling performance, high rate capability, and high Coulombic efficiency compared with pure Fe ₂O₃ particles and Fe₃O₄/CNT composites. The CNT@Fe₃O₄@C nanocables deliver a reversible capacity of 1290 mA h g^-1 after 80 cycles at a current density of 200 mA g^-1, and maintain a reversible capacity of 690 mA h g^-1 after 200 cycles at a current density of 2000 mA g^-1. The improved lithium storage behavior can be attributed to the synergistic effect of the high electronic conductivity support and the inner CNT/outer carbon buffering matrix. In charge: Carbon nanotube (CNT)@Fe₃O ₄@C porous core/sheath coaxial nanocables are synthesized by a simple one-pot hydrothermal process. Neither a surfactant/ligand nor a CNT pretreatment is needed in the synthetic process. The CNT@Fe₃O ₄@C nanocables show enhanced cycling performance and high rate capability when used as the anode material of lithium-ion batteries (see figure).