Porous Silica-Pillared MXenes with Controllable Interlayer Distances for Long-Life Na-Ion Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• MXenes are promising 2D materials for energy storage but suffer from limited ion accessibility.
• Existing pillaring methods for increasing interlayer spacing have seen limited success in MXenes.

Purpose of the Study:

• To develop a novel amine-assisted pillaring methodology for MXenes.
• To enhance the interlayer spacing and surface area of MXenes for improved electrochemical performance.

Main Methods:

• Amine-assisted intercalation of silica-based pillars between Ti3C2 MXene layers.
• Control of interlayer spacing via amine choice and calcination temperature.
• Characterization of intercalation mechanism and surface chemistry.

Main Results:

• Achieved a maximum interlayer spacing of 3.2 nm, the largest reported for MXenes.
• Increased BET surface area to 235 m2 g-1, a sixty-fold enhancement.
• Demonstrated superior Na-ion battery capacity, rate capability, and stability (98.5% capacity retention).

Conclusions:

• Amine-assisted pillaring is an effective method for optimizing MXene properties.
• Pillared MXenes show significant potential for advanced energy storage applications.
• This technique offers a new approach for tailoring MXenes for diverse applications like catalysis and gas separations.