Surface modification of spinel Li4Ti5O12 with Fe for lithium ion batteries

Special capacity and cycling performance of spinel Li4Ti5O12 anode material were improved by surface modification with Fe through a facile method. The phase structures, morphologies and electrochemical performance of pristine and Fe modified Li4Ti5O12 were investigated by Xray diffraction, scanning electron microscopy, Energy dispersive X-ray spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy and charge-discharge tests. Electrochemical measurements demonstrated that the Li4Ti5O12/Fe electrode displayed enhanced special capacity and cycling performance compared with those of pristine Li4Ti5O12. The special capacity of Li4Ti5O12/Fe is 123.4 mAh g(-1) at 5C rate, much higher than 59.5 mAh g 21 of the pristine material. The Fe modified Li4Ti5O12 anode also showed superior cycling stability with an initial discharge capacity of 141 mAh g(-1) at 2C rate and still maintained 96.7% of its initial capacity after 300 cycles.