Preparation and Performance of N-doped Carbon Coated Li4Ti5O12 as Anode Material for Lithium-ion Batteries

N-doped carbon coated Li4Ti5O12 samples were synthesized by a conventional high-temperature solid method with ball milled TiO2, Li2CO3 and polyaniline(PANT) as the titanium source, lithium source and carbon/nitrogen source, respectively. The structure and morphology of the samples were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), elemental analysis(EA), scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The electrochemical performance of the samples as the anode material for lithium-ion batteries was evaluated. The results indicate that the treatment of titanium source affect the electrochemical properties of samples. N-doped carbon coated Li4Ti5O12 obtained by pre-coating process of TiO2 showed the best electrochemical behaviors when the coating ratio of carbon/nitrogen source was 5%. The specific capacity of the electrode reached 157. 6 mA. h/g at 1 C and retained to be 119. 6 mA . h/g at a high current density of 20 C. It remained 97. 8% of initial capacity after 100 cycles at 10 C.