Nitridation Br-doped Li4Ti5O12 anode for high rate lithium ion batteries

• Br doping Li4Ti5O12 powder was synthesized by solid state reaction.
• TiN layer formed on the surface of Li4Ti5O11.7Br0.3 powder after heating in NH3.
• The TiN coated Li4Ti5O11.7Br0.3 shows superior electrochemical performance.

Br-doping Li4Ti5O12 (Li4Ti5O11.7Br0.3) is fabricated by conventional solid state method and shows enhanced cycling performance compared with pristine Li4Ti5O12. After thermal nitridation for 90 min in NH3, the Li4Ti5O11.7Br0.3 electrode exhibits better rate capability and excellent cycling performance. It delivers a reversible capacity of 138 mAh g−1 and 104 mAh g−1 after 100 cycles at 10C and 20C, respectively, which is approximately four and seven times higher than those of pristine Li4Ti5O12 at the same current rates. This work indicates the feasibility of improving cycling performance and rate capabilities of Li4Ti5O12 through controlling both surface termination and bulk doping procedures.