Li4Ti5O12-coated graphite as an anode material for lithium-ion batteries

Abstract

In this study, we have synthesized and characterized Li4Ti5O12 (LTO)-coated meso-carbon micro beads (MCMB) as an anode material for Li-batteries. The surface of MCMB powders was uniformly coated by the LTO nanoparticles to form a core–shell structure via a sol–gel process, followed by calcination. The average size of MCMB core was 20μm while the thickness of LTO shell was 80–120nm. We found that LTO-coated MCMB has better rate-capability and cycle life, compared with the pristine MCMB. Electrochemical impedance spectroscopy (EIS) results showed that after 40 cycles, the cell resistance of the LTO-coated MCMB electrode increased slightly, while that of the pristine MCMB electrode increased significantly. The enhanced performance of the LTO-coated MCMB electrode is attributed to the LTO coating, which suppresses the increase in the charge-transfer resistance during prolonged cycle.