Electrospun TiO ₂-graphene composite nanofibers as a highly durable insertion anode for Lithium ion batteries

We report the synthesis and electrochemical performance of one-dimensional TiO ₂-graphene composite nanofibers (TiO ₂-G nanofibers) by a simple electrospinning technique for the first time. Structural and morphological properties were characterized by various techniques, such as X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and BET surface area analysis. Lithium insertion properties were evaluated by both galvanostatic and potentiostatic modes in half-cell configurations. Cyclic voltammetric study reveals the Li-insertion/extraction by a two-phase reaction mechanism that is supported by galvanostatic charge-discharge profiles. Li/TiO ₂-G half-cells showed an initial discharge capacity of 260 mA h g ^-1 at current density of 33 mA g ^-1. Further, Li/TiO ₂-G cell retained 84% of reversible capacity after 300 cycles at a current density of 150 mA g ^-1, which is 25% higher than bare TiO ₂ nanofibers under the same test conditions. The cell also exhibits promising high rate behavior with a discharge capacity of 71 mA h g ^-1 at a current density of 1.8 A g ^-1.