Ionothermally Synthesized Nanoporous Ti0.95W0.05Nb2O7: a Novel Anode Material for High-Performance Lithium-Ion Batteries

Although TiNb2O7 is regarded as a fast-rechargeable lithium-ion battery (LIB) anode material, the intrinsic poor electrochemical kinetics of TiNb2O7 still dramatically impedes its development. Herein, an ionothermal synthesis-assisted doping strategy is proposed for the preparation of a new W6+-doped TiNb2O7 material (Ti0.95W0.05Nb2O7) with nanoporous structure (denoted as NPTWNO). The improved Li+ diffusion coefficient of NPTWNO suggests that the ionic-liquid-templated nanoporous architecture improves the Li+ diffusion kinetics. The density functional theory computational study reveals that the doped W6+ successfully boosts the electronic conductivity due to the narrowed conduction-valance bandgap resulted from charge redistribution, which is reflected by the electrochemical impedance spectroscopy data. With the simultaneously enhanced Li+ diffusivity and electronic conductivity, NPTWNO achieves fast-rechargeability in LIBs. Therefore, this work indicates the potential of ionothermal synthesis-assisted doping strategy on energy storage materials and offers NPTWNO material with promising electrochemical performance.

Automated summary

A new W6+-doped TiNb2O7 material with a nanoporous structure (NPTWNO) was prepared through an ionothermal synthesis-assisted doping strategy. The improved Li+ diffusion coefficient of NPTWNO suggests that the ionic-liquid-templated nanoporous architecture enhances Li+ diffusion kinetics. The doped W6+ successfully boosts the electronic conductivity by narrowing the conduction-valance bandgap, as revealed by the density functional theory computational study.