Synthesis and Electrochemical Properties of C/Li₄Ti₅O₁₂ Powders by Spray Pyrolysis Using Aqueous Solution of Organic Acid

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Spherical C/Li₄Ti₅O₁₂ fine powders were successfully prepared by the ultrasonic spray pyrolysis using aqueous solution of Li and Ti with organic compound. C/Li₄Ti₅O₁₂ particles were crystallized to spinel structure with Fd3m space group at more than 600°C. The carbon content of C/Li₄Ti₅O₁₂ powders was 5 wt% from DTG analysis. Chemical analysis revealed that the molar ratio of Li/Ti of C/Li₄Ti₅O₁₂ powders was agreement with the starting solution component. The electrochemical properties of C/Li₄Ti₅O₁₂ anode were also estimated by rechargeable capacity, cycle life, thermal stability and high rechargeable rate. The use of lactic acid as a carbon source was most effective for improvement of them. The rechargeable capacity of C/Li₄Ti₅O₁₂ anode increased with increasing carbon contents and it exhibited 165 mAh g⁻¹ at 1 C. The rechargeable capacity of C/Li₄Ti₅O₁₂ decreased with increasing charge rate and that of C/Li₄Ti₅O₁₂ was 150 mAh g⁻¹ at 10 C, but the stable cycle life was also maintained at 10 C. The cycle stability of C/Li₄Ti₅O₁₂ anode was also kept at 50°C.