Carbon composite spun fibers with in situ formed multicomponent nanoparticles for a lithium-ion battery anode with enhanced performance

Carbon composite fibers with Fe3O4, Fe3C, and TiO2 nanoparticles (Fe3O4/Fe3C/TiO2/C) were successfully fabricated using a facile dry-spinning approach, followed by annealing under argon flux. When used as the anode material of a lithium-ion battery, the Fe3O4/Fe3C/TiO2/C composite fibers achieved a reversible capacity of 702.1 mA h g(-1) after 400 cycles at a current density of 100 mA g(-1) and ca. 200 mA h g(-1) at a current density of 1000 mAg(-1) in 350 cycles. The superior cycling performance and high rate capability were attributed to the high theoretical specific capacity of Fe3O4, the catalytic activity of Fe3C, the structural stability of TiO2, and the buffer function of carbon fiber. Compared with the corresponding Fe3O4/Fe3C/C and TiO2/C composite fibers, the Fe3O4/Fe3C/TiO2/C product exhibited higher cycling and rate performances due to the synergetic effect among the Fe3O4, Fe3C, TiO2 and carbon components.