Constructing Artificial SEI Layer on Lithiophilic MXene Surface for High-Performance Lithium Metal Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• MXene materials show promise for lithium metal anodes due to high surface area and lithiophilicity.
• Challenges remain in preventing lithium dendrite growth and dead lithium formation during cycling.
• A robust interface layer is crucial for stable lithium metal anode performance.

Purpose of the Study:

• To develop a stable artificial solid electrolyte interface (SEI) on MXene surfaces.
• To regulate homogeneous lithium plating and stripping for improved battery performance.
• To enhance the long-term cycling stability and safety of lithium metal batteries.

Main Methods:

• Constructing a 2D/2D MXene/g-C3N4 composite nanosheet heterostructure.
• Utilizing insulating g-C3N4 to form a protective artificial SEI layer on MXene.
• Characterizing the electrochemical performance of the modified MXene anode in lithium metal batteries.

Main Results:

• The Ti3C2Tx/g-C3N4 electrode demonstrated conformal lithium deposition.
• Achieved an average Coulombic efficiency (CE) of 98.4% over 400 cycles.
• Full cells with LiFePO4 cathodes showed 85.5% capacity retention after 320 cycles.

Conclusions:

• The 2D/2D lithiophilic layer/artificial SEI heterostructure effectively suppresses lithium dendrites.
• This strategy significantly enhances the Coulombic efficiency and cycle lifespan of lithium metal anodes.
• The findings offer valuable insights for designing high-performance and stable lithium metal batteries.