Flotation separation in lithium-ion battery recycling: Challenges and recent advances

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Increasing electric vehicle and electronics use drives demand for lithium-ion batteries (LIBs).
• Limited LIB lifespan necessitates efficient recycling to recover valuable materials and mitigate environmental impact.
• Separating anode and cathode materials is key for LIB recycling, but challenging due to complex compositions.

Purpose of the Study:

• To review the principles and applications of froth flotation for spent LIB recycling.
• To examine the role of flotation agents in enhancing anode-cathode separation.
• To identify challenges and pretreatment strategies for optimizing flotation efficiency in LIB recycling.

Main Methods:

• Review of fundamental froth flotation principles.
• Analysis of flotation agents (collectors, frothers, dispersants) and their impact on electrode material hydrophobicity.
• Exploration of pretreatment methods to improve flotation performance.

Main Results:

• Froth flotation leverages inherent hydrophobicity differences between anode (e.g., graphite) and cathode (e.g., lithium metal oxides) materials.
• Flotation agents significantly influence separation efficiency, requiring careful selection and optimization.
• Pretreatment strategies can overcome challenges like binders, residual lithium, and surface degradation.

Conclusions:

• Froth flotation is a viable, structure-preserving technique for separating anode and cathode materials in spent LIBs.
• Optimizing flotation agents and employing pretreatment methods are essential for efficient and sustainable LIB recycling.
• This review provides insights for advancing large-scale, eco-friendly LIB recovery technologies.