Preparation and electrochemical performance of La3+ and F- co-doped Li4Ti5O12 anode material for lithium-ion batteries

La3+ and F- co-doped Li4Ti5O12 (LTO) anode materials are synthesized successfully via a solid state reaction. The structure and morphology are characterized by XRD, SEM and EDS. The results indicate that La3+ and F- ions were uniformly dispersed in Li4Ti5O12 lattice without changing the structure and morphology of Li4Ti5O12 Li3.95La0.05Ti5O11.7F0.3 (La005-F03) exhibits an outstanding electrochemical performance among all the samples in a potential range from 0.5 to 2.5 V, and delivers a discharge capacity of 103 mAh g(-1) at 10C rate, whereas the LTO only gives 62.5 mAh g. The sample La005-F03 retains a discharge capacity of 170.1 mAh g(-1) after 100 cycles at 1C rate. The improved electrochemical performance could be attributed to the appropriate co-doping with La3+ and F-, which can increase the amount of Ti3+/Ti4+ mixing as charge compensation, leading to the decrease of the charge transfer resistance and improvement of the electronic conductivity and lithium ion diffusion coefficient. (C) 2014 Elsevier B.V. All rights reserved.