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

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 TiCl(4) as the raw material has been developed to prepare spherical precursor. High tap density spherical Li(4)Ti(5)O(12) is synthesized by sintering the mixture of precursor and Li(2)CO(3). La-doped Li(4)Ti(5)O(12) 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 Li(4)Ti(5)O(12) powders prepared by this method are spherical and exhibits high tap density. La(3+) dopant improved the electrochemical performance over the pristine Li(4)Ti(5)O(12). It is tested that the tap density of the pristine and La(3+)-doped products is as high as 1.80 and 1.78 gaEuro cent cm(-3), respectively. Between 1.0 and 3.0 V versus Li, the initial discharge capacity of the La(3+) dopant is as high as 161.5 mAhaEuro cent g(-1) at 0.1C rate. After 50 cycles, the reversible capacity is still 135.4 mAhaEuro cent g(-1).