Silicon Nitride-Enabled Mechanical Reinforcement and Interfacial Catalysis Toward Highly Stable Silicon-Based Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Silicon suboxide (SiOx) offers high capacity for lithium-ion batteries but suffers from volume expansion and instability.
• Existing methods like carbon coating offer limited mechanical buffering for SiOx anodes.
• Developing robust SiOx anodes requires strategies addressing both mechanical degradation and interfacial issues.

Purpose of the Study:

• To develop a synergistic modification strategy for silicon-based anodes.
• To enhance the mechanical stability and interfacial properties of SiOx anodes.
• To improve the cycling stability and practical applicability of high-energy-density batteries.

Main Methods:

• Incorporation of ceramic silicon nitride (Si3N4) into SiOx via high-energy ball milling (HEBM).
• Formation of a SiOx-Si3N4 composite anode (SiOx@Si3N4-HEBM).
• Characterization of structural, electrochemical, and interfacial properties.

Main Results:

• The SiOx@Si3N4-HEBM anode demonstrated suppressed volume expansion and particle agglomeration.
• Si3N4 catalyzed the formation of a Li3N-rich solid electrolyte interphase (SEI), improving ion transport.
• Capacity retention improved from 38.89% to 64.36% after 100 cycles at 0.5 C, with enhanced rate capability and reduced impedance.

Conclusions:

• Synergistic mechanical reinforcement and interfacial catalysis effectively improve SiOx anode performance.
• The SiOx@Si3N4-HEBM composite offers a promising strategy for stable, high-energy-density lithium-ion batteries.
• This approach highlights the potential of coupled regulation for advanced battery materials.