Preparation of SnO2/TiO2/C composite fibres and their use as binder-free anodes for lithium-ion batteries

Tin dioxide/titanium dioxide/flexible and carbon fibres ((SnO2/TiO2)/FPCFs) were fabricated via centrifugal spinning (CS) of precursor solutions and used as binder-free anode materials in lithium-ion batteries (LIBs). The SnO2/TiO2/FPCFs were prepared by CS of tin (II) 2-ethylhexanoate/titanium (IV) butoxide/polyvinylpyrrolidone, followed by calcination at 700 degrees C to yield SnO2/TiO2 short fibres. The as-obtained fibres were crushed and mixed in ethanol to form a SnO2/TiO2/ethanol solution. Polyacrylonitrile/polymethyl methacrylate (PAN/PMMA) fibrous mats were also prepared via CS of PAN/PMMA/DMF solutions and were coated with the SnO2/TiO2/ethanol solution and then heat-treated to yield SnO2/TiO2/FPCFs. The structure and morphology of the composite fibres were investigated by scanning electron microscope, energy dispersive X-ray spectrometer), transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis. When used as binder-free anodes for LIBs, the (3:2) (SnO2:TiO2)/FPCFs exhibited a high reversible capacity of 890 mAh g(-1) and demonstrated an outstanding columbic efficiency of 98% after 100 charge/discharge cycles at a current density of 100 mAh g(-1) and good rate capability. For comparison, the electrochemical results of (SnO2)/FPCFs and (SnO2/TiO2)/FPCFs with 1:1 (SnO2:TiO2) ratio are also reported.