Lithiophilic Three-Dimensional Porous Ti₃C₂T-rGO Membrane as a Stable Scaffold for Safe Alkali Metal (Li or Na)...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Metallic anodes offer high capacity but suffer from dendrite formation, limiting battery lifespan and safety.
• Dendritic growth and low Coulombic efficiency are critical challenges in developing high-performance alkali metal batteries.
• MXene materials show promise for battery applications due to their unique properties.

Purpose of the Study:

• To develop dendrite-free and flexible 3D alkali metal anodes for improved battery performance and safety.
• To investigate the mechanism of uniform alkali metal deposition on a 3D MXene-based host.
• To evaluate the electrochemical stability and cycling performance of the novel anode materials.

Main Methods:

• Constructed 3D alkali anodes by infusing molten lithium (Li) or sodium (Na) into 3D porous MXene Ti₃C₂T-reduced graphene oxide (Ti₃C₂T-rGO) membranes.
• Utilized first-principles calculations to understand the interaction between alkali metals and the Ti₃C₂T-rGO surface.
• Performed electrochemical testing, including stripping/plating, cycling stability, and full-cell performance evaluation.

Main Results:

• Achieved dendrite-free Li/Na deposition on the 3D Ti₃C₂T-rGO host, preventing short-circuiting.
• Demonstrated stable stripping/plating behavior up to 12 mA·cm^-2 with a capacity of 10 mA·h·cm^-2.
• Exhibited excellent cycling stability over 750 cycles for both Li and Na anodes, with Li-Ti₃C₂T-rGO retaining 96.6% capacity after 1000 cycles in a full cell.

Conclusions:

• The 3D porous MXene Ti₃C₂T-rGO structure effectively suppresses alkali metal dendrite growth.
• The formation of Ti-Li/Na, O-Li/Na, and F-Li/Na bonds is crucial for uniform alkali metal deposition.
• This 3D host approach offers a practical pathway for developing stable and safe alkali metal anodes for next-generation batteries.