Microemulsion-assisted synthesis of ultrafine Li4Ti5O12/C nanocomposite with oleic acid as carbon precursor and particle size controller

Ultrafine Li 4 Ti 5 O 12 /C composite is synthesized by microemulsion with oleic acid as carbon precursor and particle size controller. The as-prepared sample is characterized with X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), thermogravimetry analysis (TGA) and nitrogen absorption–desorption isotherms, and its performance as anode of lithium ion battery is determined with charge–discharge test and electrochemical impedance spectroscopy (EIS). The characterizations show that the as-prepared sample is composed of ultrafine Li 4 Ti 5 O 12 particles with average size of 25 nm, which are uniformly dispersed in carbon matrix with a carbon content as low as 2.69 wt%. Charge–discharge test indicates that the as-prepared sample exhibits excellent rate performance and cycling stability. At 10C, the highest discharge capacity reaches 136.3 mAh g −1 and the capacity retention is 96.4% after 100 cycles. The improved performance of the Li 4 Ti 5 O 12 /C composite is attributed to the ultrafine particle size and the uniform composite of Li 4 Ti 5 O 12 with carbon.