Preparation and characterization of spherical La-doped Li4Ti5O12 anode material for lithium ion batteries

Abstract

The lithium secondary batteries with high power density need the electrode materials with both high specific capacity and high tap density. An “outer gel” method by TiCl4 as the raw material has been developed to prepare spherical precursor. High tap density spherical Li4Ti5O12 is synthesized by sintering the mixture of precursor and Li2CO3. La-doped Li4Ti5O12 is also prepared by this method. X-ray diffraction, scanning electron microscopy, energy-dispersive spectrometry, tap density testing, and the determination of the electrochemical properties show that the Li4Ti5O12 powders prepared by this method are spherical and exhibits high tap density. La3+ dopant improved the electrochemical performance over the pristine Li4Ti5O12. It is tested that the tap density of the pristine and La3+-doped products is as high as 1.80 and 1.78 g•cm−3, respectively. Between 1.0 and 3.0 V versus Li, the initial discharge capacity of the La3+ dopant is as high as 161.5 mAh•g−1 at 0.1C rate. After 50 cycles, the reversible capacity is still 135.4 mAh•g−1.