Nitrogen doped CNT/Li4Ti5O12 composite for the improved high-rate electrochemical performance of lithium-ion batteries

A novel Li4Ti5O12 (LTO) composite with nitrogen doped multi-walled carbon nanotubes (CNTs), denoted N-C-LTO, was successfully prepared via simple thermal annealing of CNTs in the presence of melamine. For comparison, LTO, C-LTO (Li4Ti5O12/CNT) were also synthesized. N-C-LTO demonstrated the best electrochemical performance among the samples. Even at a high charge/discharge rate of 20 C, the reversible capacity was maintained at the high level of 100 mAhg-1. Moreover, after 150 cycles at 3.0 C, 90.7 % of the capacity was retained with negligible capacity fading. The excellent electrochemical performance was possibly due to the nitrogen in the doped CNTs, which maintained the benefits of the nitrogen as good electron donating.