Centrifugally spun α-Fe₂O₃/TiO₂/carbon composite fibers as anode materials for lithium-ion batteries

We report results on the electrochemical performance of flexible and binder-free α-Fe₂O₃/TiO₂/carbon composite fiber anodes for lithium-ion batteries (LIBs). The composite fibers were produced via centrifugal spinning and subsequent thermal processing. The fibers were prepared from a precursor solution containing PVP/iron (III) acetylacetonate/titanium (IV) butoxide/ethanol/acetic acid followed by oxidation at 200 °C in air and then carbonization at 550 °C under flowing argon. The morphology and structure of the composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These ternary composite fiber anodes showed an improved electrochemical performance compared to the pristine TiO₂/C and α-Fe₂O₃/C composite fiber electrodes. The α-Fe₂O₃/TiO₂/C composite fibers also showed a superior cycling performance with a specific capacity of 340 mAh g^-1 after 100 cycles at a current density of 100 mA g^-1, compared to 61 mAh g^-1 and 121 mAh g^-1 for TiO₂/C and α-Fe₂O₃/C composite electrodes, respectively. The improved electrochemical performance and the simple processing of these metal oxide/carbon composite fibers make them promising candidates for the next generation and cost-effective flexible binder-free anodes for LIBs.