Rational synthesis of ternary FeS@TiO2@C nanotubes as anode for superior Na-ion batteries

Na-ion batteries (SIBs) have now attractive extensive attention due to the wide-spread preserve of sodium resources and low cost, which have the potential as the alternative for Li-ion batteries and suitable for large energy station application. Herein, we have rationally synthesized uniform nanotube-structured FeS@TiO2@ C anode with metal-organic framework (Fe-MOF) rods as the self-support template. Such uniform ternary FeS@TiO2@C nanotubes were facilely prepared by sulfuration of FeTiO3@C nanotubes, which were obtained by a one-pot annealing of TiO2-coated Fe-MOF nanorods. This carbon-wrapped hollow nanostructure could effectively mitigate the volume expansion, improve the electronic conductivity and provide more channels and active sites for Na+ transporting. In detail, these uniform FeS@TiO2@C nanotubes achieve superior rate capability (with a high reversible capacity of 387, 390, 376, 348, 325, and 286 mA h g(-1) at the current density of 0.1, 0.2, 0.5, 1.0, 2.0, and 5.0 A g(-1), respectively) and excellent cycling performance (with a reversible capacity of 454 mA h g(-1) after 120 cycles at 0.2 A g(-1) and 406 mA h g(-1) after 150 cycles at 1.0 A g(-1)).