Lithium Pre-Storage Enables High Initial Coulombic Efficiency and Stable Lithium-Enriched Silicon/Graphite Anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Silicon anodes face challenges with low initial Coulombic efficiency (ICE) and poor cyclability.
• Traditional pre-lithiation reagents lack stability and pose safety risks.
• Developing water-stable, high-ICE prelithiated silicon is crucial for advanced batteries.

Purpose of the Study:

• To develop a stable and effective pre-lithiation method for silicon anodes.
• To enhance the initial Coulombic efficiency (ICE) and cycling stability of silicon-based anodes.
• To create air- and water-stable prelithiated silicon materials.

Main Methods:

• A novel lithium pre-storage methodology using nano-drilled graphite with surficial lithium functional groups.
• High-temperature sintering to form chemical bonds between lithium functional groups on graphite and silicon nanoparticles.
• In situ pre-lithiation of silicon nanoparticles via an O-Li-Si interaction.

Main Results:

• Achieved an ultra-high initial Coulombic efficiency (ICE) of ≥110%.
• Demonstrated excellent air and water stability of the lithium-enriched silicon/graphite material.
• Exhibited a high specific capacity of 620 mAh g⁻¹ and long cycling stability (>400 cycles).

Conclusions:

• The developed lithium pre-storage method offers a promising solution for stable silicon anode pre-lithiation.
• This approach overcomes the limitations of traditional pre-lithiation reagents, enhancing safety and performance.
• The lithium-enriched silicon/graphite material paves the way for next-generation high-performance, stable batteries.