Covalently Anchored MXene-Infiltrated Porous Silicon for Mechanically Resilient Lithium-Ion Battery Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Silicon anodes offer high theoretical capacity for lithium-ion batteries.
• Volume expansion and instability hinder practical silicon anode application.
• Existing surface coating methods have limitations in addressing silicon anode degradation.

Purpose of the Study:

• To engineer a covalently integrated MXene-infiltrated porous silicon (MPSi) architecture.
• To enhance mechanical resilience, electronic conductivity, and interfacial stability of silicon anodes.
• To overcome the limitations of conventional silicon anode designs for high-energy batteries.

Main Methods:

• Infiltration of few-layer Ti3C2Tx MXene nanosheets into porous silicon using ethanol-assisted wetting and vacuum impregnation.
• Mild annealing to induce covalent Si-O-Ti bonds between MXene and silicon.
• Characterization of the MPSi architecture and electrochemical performance evaluation in half and full cells.

Main Results:

• The MPSi anode demonstrated a high reversible capacity of 906.3 mAh g-1 after 300 cycles at 1 A g-1.
• Excellent rate capability was achieved, with 543.3 mAh g-1 at 5 A g-1.
• Full cells with NCM811 cathodes showed 80.2% capacity retention after 200 cycles, indicating practical viability.

Conclusions:

• The covalently bonded MXene-Si architecture effectively addresses mechanical and electrochemical degradation of silicon anodes.
• The MPSi anode offers a scalable strategy for developing next-generation high-energy lithium-ion batteries.
• The study highlights the potential of infiltration-driven, covalently bonded architectures for advanced battery materials.