Li4Ti5O12-coated graphite anode materials for lithium-ion batteries

Abstract

In this study, we synthesized and characterized Li4Ti 5O12 (LTO)-coated graphite as an anode material for Li-batteries. The surface of graphite powders was uniformly coated by the LTO nanoparticles to form a core-shelled structure via a sol-gel process, followed by calcination. The average size of graphite core was 20 μm while the thickness of LTO shell was 60 nm to 100 nm. We found that LTO-coated graphite has better rate-capability and cycle life at RT and 55 C, compared with the pristine graphite. The electrochemical impedance spectroscopy (EIS) results of the cell with LTO-coated graphite anode showed a significant suppression of the impedance rise after 60 cycles. In addition, the Raman spectrum showed that after 60 charge-discharge cycles at 55 C, the ID/IG ratio of the LTO-coated graphite electrode increased slightly, while that of the pristine graphite electrode increased significantly. The batteries with LTO-coated graphite anode exhibited excellent cyclic ability and high temperature performance. © 2013 Published by Elsevier Ltd.