Synthesis and electrochemical properties of Li₄Ti₅O₁₂ nano-crystalline by nonaqueous sol-gel method

Nano-sized Li₄Ti₅O₁₂ powders with high dispersivity were prepared by a novel sol-gel route using lauric acid as surfactant. The crystal structure, microstructure and the electrochemical properties of the samples were characterized by XRD, SEM, TG-DSC and galvanostatically charge-discharge experiments. The effects of molar ratio of Li to Ti, the content of surfactant and the calcining temperature on the phase structure, the microstructure and the electrochemical properties were studied to optimize process. The results demonstrated that the crystallization, microstructure and electrochemical properties were influenced significantly by the content of the surfactant. Li₄Ti₅O₁₂ powders calcined at 800°C for 10h comprised of crystallites with the particle size in the range 100-300nm revealing high dispersivity almost without any agglomerates, exhibiting an excellent electrochemical performance. Its discharge capacity at 1 and 2C rates can reach 163.3 and 132.3mAh/g, respectively. After 50 cycles, fairly stable cycling performance was achieved without obvious capacity fade.