Ta-doped Nb₂O₅ with enhanced performance for lithium-ion batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Niobium pentoxide (Nb2O5) is a promising anode material for high-volumetric-energy-density lithium-ion batteries (LIBs) due to its safety and fast ion transport.
• However, practical application of Nb2O5 is limited by structural instability and capacity fading during cycling.

Purpose of the Study:

• To enhance the electrochemical performance and stability of Nb2O5 anodes for LIBs.
• To investigate the effect of tantalum (Ta) doping on the structural and electrochemical properties of Nb2O5.

Main Methods:

• Synthesis of Ta-doped Nb2O5 (Ta0.2Nb2O5.5) materials.
• Electrochemical characterization including cyclic voltammetry, galvanostatic charge-discharge cycling, and electrochemical impedance spectroscopy.
• Structural analysis using techniques like X-ray diffraction and electron microscopy.

Main Results:

• Ta-doped Nb2O5 exhibited improved structural stability and enhanced lithium insertion/deinsertion kinetics.
• The optimized Ta0.2Nb2O5.5 anode delivered a specific capacity of 86 mA h g-1 at 20 A g-1 and retained 64% capacity over 1000 cycles at 8 A g-1.
• A full cell using Ta0.2Nb2O5.5 as anode showed significantly improved capacity retention and rate capability compared to undoped Nb2O5.

Conclusions:

• Tantalum doping effectively improves the lattice stability and charge transfer properties of Nb2O5 anodes.
• The enhanced performance of Ta-doped Nb2O5 makes it a superior candidate for high-performance LIBs.
• This doping strategy offers a promising route for developing advanced niobium-based electrode materials.