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

La 3+ and F − co-doped Li 4 Ti 5 O 12 (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 La 3+ and F − ions were uniformly dispersed in Li 4 Ti 5 O 12 lattice without changing the structure and morphology of Li 4 Ti 5 O 12 . Li 3.95 La 0.05 Ti 5 O 11.7 F 0.3 (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 −1 . 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 La 3+ and F − , which can increase the amount of Ti 3+ /Ti 4+ mixing as charge compensation, leading to the decrease of the charge transfer resistance and improvement of the electronic conductivity and lithium ion diffusion coefficient .