Synthesis and Electrochemical Properties of Lithium Titanate Anode Materials Powders by Solid State Reaction of Li and Spherical TiO_2 Powders

摘要

Li_4Ti_5O_(12) powders were synthesized by solid state reaction of Li_2CO_3 and spherical composite powders of carbon and TiO_2 (denoted as C/TiO_2). C/TiO_2 powders were synthesized by spray pyrolysis of using lactic acid aqueous solution. The particle characteristics of Li_4Ti_5O_(12) powders were determined by SEM, XRD and DTA-TG. DTA-TG showed that the carbon content was around 8 wt% in Li_4Ti_5O_(12) powders. XRD revealed that the spinel structure (Fd3m) was obtained by heating at 750 °C under N_2 atmosphere. The first rechargeable capacity of Li_4Ti_5O_(12) anode was about 160 mAh/g at 1 C. That of Li_4Ti_5O_(12) anode decreased to 90 mAh/g at 20 C. The rechargeable capacity of Li_4Ti_5O_(12) anode decreased with increasing the rechargeable rate, but 81% of initial discharge capacity of Li_4Ti_5O_(12) anode was retained after 200 cycles at 1C.