Enhanced intercalation dynamics and stability of engineered micro/nano-structured electrode materials: vanadium oxide...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Vanadium dioxide (VO2) is a promising material for lithium-ion batteries.
• VO2 (B) often suffers from capacity fading due to structural instability during cycling.
• Developing stable and high-performance VO2 (B) electrodes remains a challenge.

Purpose of the Study:

• To develop an additive and template-free synthesis for VO2 (B) mesocrystals.
• To investigate the structure and formation mechanism of these mesocrystals.
• To evaluate their performance as cathodic electrode materials for lithium-ion batteries.

Main Methods:

• Solvothermal reaction of oxalic acid and vanadium pentoxide.
• Characterization using selected area electron diffraction and electron microscopy.
• Electrochemical testing for lithium-ion battery performance.

Main Results:

• Facile synthesis of VO2 (B) mesocrystals with six-armed star architectures.
• Mesocrystals exhibit homoepitaxial orientation of stacked nanosheets along the [100] crystallographic direction.
• Demonstrated good capacity (195 mA h g⁻¹ over 50 cycles) and cyclic stability at high discharge rates.

Conclusions:

• The unique mesocrystalline structure provides large surface area and short diffusion paths for efficient lithium-ion intercalation.
• Homoepitaxial stacking enhances structural integrity, mitigating capacity fading.
• These VO2 (B) mesocrystals show significant potential as advanced electrode materials for lithium-ion batteries.