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

Abstract

TiNb2O7 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 TiNb2O7@N-doped carbon composite is successfully synthesized as the anode material for LIBs. Impressively, TiNb2O7@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, LiNi0.5Mn0.3Co0.2O4∥TiNb2O7@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 TiNb2O7 for LIB application by structural engineering.

High-pressure bandgap engineering and amorphization in TiNb2O7 single crystals

“…Niobate compounds have excellent electrical, optical, and magnetic properties and have extensive application in wireless communication technologies, [1][2][3] in the electro-optical field, 4,5 and in photonic devices. [6][7][8] As one of the famous niobate compounds, the structure of TiNb 2 O 7 is monoclinic with the space group I12/m1.…”

Facile Synthesis of Hierarchical CoSeO3‧2H2O Nanoflowers Assembled by Nanosheets as a Novel Anode Material for High-Performance Lithium-Ion Batteries

“…Obviously, the hierarchical structure of the sample can be maintained even after long and intensive battery operation, suggesting the excellent electrochemical stability. In addition, the discharge capacity of the electrode is slightly increased from the first to the fiftieth cycle and then slowly decreased during the following cycles, which may be attributed to the gradual electrolyte penetration and the reversible growth of the electrochemistry active polymeric gel-like film by the activated electrolyte degradation [ 26 , 27 ]. Compared to other Co, Se-based anodes materials [ 12 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ], the CoSeO 3 ‧2H 2 O nanoflowers exhibit better electrochemical performance ( Table S1 ), suggesting their promising application in energy storage devices.…”

Vacancy Control in TiNb2O7: Implications for Energy Applications

“…TiNb 2 O 7 has a large theoretical capacity (∼387.7 mAh g –1 ) due to the multielectron redox chemistry. , It demonstrates excellent rate performance, undergoes rapid charging, shows good cycling stability, has low price, and is environmentally benign. − In addition, a wide lithium intercalation/deintercalation voltage window of 1.0–2.0 V vs Li + /Li minimizes undesirable Li dendrite plating and ensures safe operation under high current density charging. , But, as a wide band gap semiconductor (∼3.2 eV), the low electronic conductivity (<10 –9 S cm –1 ) of TiNb 2 O 7 is a significant shortcoming. , To mitigate this drawback and enhance the Li storage kinetics, various structural engineering approaches have been attempted. Specifically, decreasing the particle size, carbon coating, or producing complex porous nanostructures lead to improved conductivity and Li-ion transport. − Although nanoengineering comes with trade-offs, it often enhances one performance area and causes considerable problems in another.…”