Direct and Sustainable Regeneration of Spent LiCoO₂ Cathodes Using an Eco-Friendly Deep Eutectic Solvent-Based...

Area of Science:

• Materials Science
• Electrochemistry
• Green Chemistry

Background:

• Current recycling methods for spent lithium cobalt oxide (LiCoO2) cathodes, such as high-temperature roasting and metal leaching, are energy-intensive and environmentally detrimental.
• Developing sustainable and efficient recycling processes for LiCoO2 batteries is crucial due to their widespread use and the environmental concerns associated with conventional methods.

Purpose of the Study:

• To introduce a novel, low-impact recycling method for spent LiCoO2 cathode materials.
• To demonstrate the efficacy of a deep eutectic solvent (DES) as both a lithium carrier and reductant for direct material regeneration.

Main Methods:

• A deep eutectic solvent (DES) composed of glycerol and lithium chloride was employed for the direct regeneration of spent LiCoO2.
• The process operated under mild conditions (80 °C and ambient pressure), utilizing the DES to supplement lithium ions and reduce Co4+.

Main Results:

• The regenerated LiCoO2 material achieved an initial discharge capacity of 134.84 mAh g⁻¹ at 0.1 C.
• The material maintained 95% of its capacity after 200 cycles, demonstrating excellent stability.
• The DES could be reused with high efficiency, and the method restored the compositional and structural integrity of the LiCoO2.

Conclusions:

• The DES-based method offers a sustainable and efficient alternative to traditional LiCoO2 battery recycling.
• This approach significantly reduces energy consumption and environmental impact compared to pyrometallurgical and hydrometallurgical methods.
• The study highlights the economic and environmental advantages of this novel recycling strategy for spent LiCoO2 batteries.