Li-Ions Transport Promoting and Highly Stable Solid-Electrolyte Interface on Si in Multilayer Si/C through Thickness...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-ion batteries (LIBs) are crucial for energy storage, with performance limited by lithium-ion (Li-ion) transport.
• Efficient Li-ion diffusion is key to achieving high charge/discharge rates and power density in LIBs.

Purpose of the Study:

• To investigate how amorphous silicon-carbon (Si-C) interfaces in multilayer electrodes affect Li-ion transport.
• To develop a design strategy for high-performance LIB anodes using Si-C multilayer structures.

Main Methods:

• Fabrication of amorphous Si/C multilayer electrodes with specific layer thicknesses (5 nm carbon, 10 nm silicon).
• Electrochemical characterization to assess cycle performance and capacity retention.
• Electron microscopy to analyze the electrode structure and interface properties.

Main Results:

• Amorphous Si-C interfaces promote Li-ion transport both perpendicular and parallel to the interfaces after electrode cracking.
• The optimized Si-C multilayer electrode exhibits a stable solid-electrolyte interface (SEI) and excellent cycle stability.
• High retained specific capacity was observed, indicating efficient ion diffusion and structural integrity.

Conclusions:

• A micro-size hierarchical multilayer-block design strategy with optimized Si/C stacking is proposed for high-performance LIB anodes.
• The findings provide a reference for designing advanced core-shell LIB anodes.
• This approach enhances Li-ion transport and stability in LIB electrodes.