Preparation and Characterization of Dy-doped Lithium Titanate ( Li4Ti5O12)

For the first time, Dy (Dysprosium)-doped lithium titanate (Li4Ti5O12, LTO) (denoted as Dy-LTO) was prepared by a sol-gel method assisted high temperature solid-state reaction, and the influence of Dy content on the electrochemical performance of LTO was thoroughly examined. The structure and morphology of the as-synthesized materials were mainly probed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the electrochemical performance of the prepared samples was studied using cyclic voltammometry (CV), galvanostatic charge-discharge tests and electrochemical impedance spectroscopy (EIS) measurements. The obtained XRD patterns strongly demonstrated the formation of crystalline Dy-doped Li4Ti5O12. SEM images indicated that when the atomic ratio of Dy to Ti was 0.06:4.94, some irregular smaller particles were found to be anchored on the surface of some huge particles. The results of electrochemical measurements revealed that Li4Ti4.94Dy0.06O12 sample exhibited a specific capacity of 145 mAh g-1 after 20 cycles at a current rate of 0.5 C, which was much larger than that of pristine Li4Ti5O12 (104 mAh g-1 ) and Li4Ti4.8Dy0.2O12 (101 mAh g-1 ).