Polydopamine-derived N-doped carbon-coated porous TiNb₂O₇ microspheres as anode materials with superior rate performance for lithium-ion batteries

TiNb2O7 is considered as a promising anode material for high-power lithium-ion batteries (LIBs) due to its significantly high rate performance, safety, and reversible capacity. However, its application is limited by its sluggish Li-ion diffusion kinetics and poor electrical conductivity. Herein, N-doped carbon-coated porous TiNb2O7 microspheres were successfully synthesized via solvothermal route and the subsequent carbonization process using polydopamine as a nitrided and carbon precursor. The resulting TiNb2O7@N-C composite exhibited a significant high-rate capability (201 mAh g(-1) at 30 C) and superior cycling stability (capacity retention of 97.1% at 10 C after 500 cycles). Additionally, the TiNb2O7@N-C composite also performed well in a LiNi0.5Mn0.3Co0.2O4 parallel to TiNb2O7@N-C full cell (128 mAh g(-1)at 10 C after 500 cycles with a capacity retention of 91.7%). These results indicate that the TiNb2O7@N-C composite possesses significant potential for application as an anode material for next-generation high-rate LIBs. (C) 2020 Elsevier Ltd. All rights reserved.