Preparation and characterization of novel spinel Li4Ti5O12−xBrx anode materials

Br-doped Li4Ti5O12 in the form of Li4Ti5O12−xBrx (0 ≤ x ≤ 0.3) compounds were successfully synthesized via solid state reaction. The structure and electrochemical properties of the spinel Li4Ti5O12−xBrx (0 ≤ x ≤ 0.3) materials were investigated. The Li4Ti5O12−xBrx (x = 0.2) presents the best discharge capacity among all the samples, and shows better reversibility and higher cyclic stability compared with pristine Li4Ti5O12, especially at high current rates. When the discharge rate was 0.5 C, the Li4Ti5O12−xBrx (x = 0.2) sample presented the excellent discharge capacity of 172 mAh g−1, which was very close to its theoretical capacity (175 mAh g−1), while that of the pristine Li4Ti5O12 was 123.2 mAh g−1 only.