Modification of Li4Ti5O12 Anode Material with Urea as Nitrogen Source for Lithium Ion Battery

Li4Ti5O12 is the most potential candidate anode material of lithium-ion power battery for hybrid electric vehicles. In order to improve its rate performance, through doping and heat treatment on Li4Ti5O12 with urea as nitrogen source, TiN high electrical conducting layer was prepared by in-situ selfgrowing on the surface of Li4Ti5O12 particles. The crystalline structure, morphology, composition and electrochemical properties were studied by XRD, SEM, TEM, EDS, Raman spectra and half cell charge/discharge performance testing. The results show that nitridated Li4Ti5O12 powers have the same diffraction peak positions of the spinel structure of Li4Ti5O12 with pristine Li4Ti5O12, and it is observed the presence of nitrogen and Raman feature vibration bands of TiN in in-situ selfgrowing a homogeneously layer on the surface of Li4Ti5O12 particles. The first discharge specific capacity of nitridated Li4Ti5O12 samples slightly decreases than pristine Li4Ti5O12 samples at 0.1C rate. However, the discharge specific capacity of the nitridated Li4Ti5O12 samples is 1.6 times higher than that of the pristine Li4Ti5O12 samples at 3C rate charge and discharge, and the capacity loss of them is only 3% at 0.1C rate after 100 cycle numbers. The results illuminate the nitridated Li4Ti5O12 samples have good electrochemical rate performances and cycling behavior.