Tailoring Sieving Pores and Electrochemical Interface Intercalation for Mechanically Resilient Recycled Micro-Silicon...

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Micron-sized silicon (Si) anodes are crucial for high-energy lithium-ion batteries, offering high capacity but facing challenges with particle deformation and limited cycle life.
• Industrialization of Si anodes is hindered by the trade-off between particle expansion during charging and maintaining efficient charge transfer.

Purpose of the Study:

• To develop a novel strategy for producing high-performance silicon anodes from photovoltaic waste.
• To overcome the mechanical limitations of silicon anodes through innovative structural design.
• To enhance the capacity, cycle life, and charging speed of lithium-ion batteries.

Main Methods:

• Utilized micron-sized silicon recovered from photovoltaic waste as the primary raw material.
• Employed electrochemical lithium alloying and rapid heating processes.
• Introduced a sieve-like porous structure via CO2 reaction and acid washing to mitigate mechanical stress.

Main Results:

• Achieved extremely high specific capacity (2493 mAh g⁻¹) and low electrode expansion (10.8%).
• Demonstrated excellent rate performance (1257 mAh g⁻¹ at 2 A g⁻¹ over 1000 cycles) with a low capacity decay rate (0.016% per cycle).
• Pouch cells reached 91.5% capacity retention over 500 cycles and a record volumetric energy density of 1428 Wh L⁻¹.
• Developed a non-destructive testing method for early safety warnings in silicon-based batteries.

Conclusions:

• The developed sieve-like porous silicon anode effectively overcomes mechanical limitations, enabling superior electrochemical performance.
• This approach offers an efficient and environmentally friendly method for utilizing photovoltaic silicon waste in advanced battery technologies.
• The new fault warning method enhances the safety and reliability of silicon-based batteries.