Ammonia‐Annealed TiO₂ as a Negative Electrode Material in Li‐Ion Batteries: N Doping or Oxygen Deficiency?

Abstract

Abstract Improving the chemical diffusion of Li ions in anatase TiO 2 is essential to enhance its rate capability as a negative electrode for Li‐ion batteries. Ammonia annealing has been used to improve the rate capability of Li 4 Ti 5 O 12 . Similarly, ammonia annealing improves the Li‐ion storage performance of anatase TiO 2 in terms of the stability upon cycling and the C‐rate capability. In order to distinguish whether N doping or oxygen deficiencies, both introduced upon ammonia annealing, are more relevant for the observed improvement, a systematic electrochemical study was performed. The results suggest that the creation of oxygen vacancies upon ammonia annealing is the main reason for the improvement of the stability and C‐rate capability.