Influence of Mechanical Processing and the Procedure Used to Introduce a Carbon Material on the Electrochemical Properties of Li4Ti5O12/C Composites

Li4Ti5O12/C anode materials of different particle size have been prepared by a sol–gel process, followed by mechanical processing in a planetary mill. Carbon was introduced both by an in situ process and by mechanically mixing lithium titanate with carbon black (Timcal). The materials thus prepared have been characterized by X-ray diffraction, electron microscopy, and low-temperature nitrogen adsorption measurements and electrochemically tested. The decrease in the particle size of Li4Ti5O12 with increasing milling rate is larger in the case of the composites containing carbon black (Timcal). At a low charge/discharge rate (0.1C), the electrochemical capacity of the composites processed in a planetary mill at rotation rates of ≤400 rpm exceeds that of the pristine Li4Ti5O12. At high current densities (18C), the Li4Ti5O12/carbon black (Timcal) composite processed at 200 rpm exhibits the highest electrochemical capacity (107 mAh/g).