One-pot sol-gel synthesis of Li4Ti5O12/C anode materials for high-performance Li-ion batteries

In this study, Li4Ti5O12/C (LTO/C) composites were successfully synthesized via a facile one-pot sol-gel method using citric acid as carbon source. The physical and electrochemical properties of the as-prepared composites were extensively investigated. These analyses signify that the uniformly coated carbon layer from citric acid on the surface of the LTO particles was found, and also resulting in the partial reduction of Ti4+ to Ti3+ after the sintering in an inert atmosphere. Owing to the synergistic effect of highly conductive carbon coating layer and the mixed valence of Ti4+/Ti3+, the synthesized LTO/C composite electrode showed the significantly improved high-rate capability and stability, which delivered initial discharge capacity of 165.7, 161.7, 153.9 and 147.9 mAh g−1 at the charge/discharge current density of 1, 5, 10, and 20 C, respectively, and the discharge capacity even retained up to 98% of that of the first cycle after the consecutive 50 cycles at 20 C. This one-pot sol-gel process may present a facile pathway for large-scale preparation of LTO/C as high-performance anode materials for lithium-ion batteries.