Porous TiNb2O7@N-C as Anode Materials for Lithium-Ion Batteries with Ultrahigh-Rate Performance

TiNb 2 O 7 has been proposed as a promising anode material for next-generation lithium-ion batteries (LIBs) owing to its high safety and cycling stability. However, its application is basically hampered by its low inherent conductivity and poor kinetic performance. Herein, a porous TiNb 2 O 7 @N-doped carbon composite is successfully synthesized as the anode material for LIBs. Impressively, TiNb 2 O 7 @N-C delivers excellent cycling performance with a Coulombic efficiency of above 99%. Even at 30C, a high specific capacity of 203 mAh g –1 could be retained, suggesting its superior rate capability. The ultrahigh-rate performance can be attributed to its special porous structure and N-doped carbon coating. Furthermore, LiNi 0.5 Mn 0.3 Co 0.2 O 4 ∥TiNb 2 O 7 @N-C full cells can deliver 86.3 mAh g –1 after 500 cycles at 10C. This work provides a feasible strategy to develop highly efficient TiNb 2 O 7 for LIB application by structural engineering.