Influence of high-energy ball milling of precursor on the morphology and electrochemical performance of Li4Ti5O12-ball-milling time

High-energy ball milling (HEBM) was applied for the synthesis of spinel Li4Ti5O12 and the influence of milling time was investigated systematically. With the increase of ball-milling time, the average particle size of the as-synthesized Li4Ti5O12 powder decreased from similar to 900 nm to similar to 150 nm, while the particle morphology changed little. At the same time, the main particle size distribution peak split up into two parts, which were narrowed and moved to a smaller range. Electrochemical testing results showed that the Li4Ti5O12 with precursor milled for 60 min at 500 rpm rotational speed showed a favorable discharge capacity of similar to 146.9 mAh/g with corresponding coulombic efficiency of 99.9% at 1 C rate. The rate performance was improved with the increase of milling time because of the smaller particle size of the resulted Li4Ti5O12. The voltage change between oxidation peak and reduction peak of Li4Ti5O12 also became wider with milling time increasing. (C) 2008 Elsevier B.V. All rights reserved.