A Closed-Loop Process for Rapid and Selective Lithium Extraction and Resynthesis from Spent LiFePO₄ Batteries

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• The increasing use of lithium iron phosphate (LFP) batteries in energy storage presents significant challenges for sustainable resource management and environmental protection.
• Efficient recovery and recycling of critical materials from spent LFP batteries are crucial for a circular economy.

Purpose of the Study:

• To develop a novel, economically feasible, and efficient method for the rapid and selective extraction of lithium from spent LFP batteries.
• To resynthesize high-performance LFP cathode materials from recovered resources.
• To evaluate the economic feasibility and environmental benefits of the proposed recycling process.

Main Methods:

• A selective leaching system using sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) was employed for rapid lithium extraction.
• High-purity lithium carbonate (Li2CO3) was obtained through optimized precipitation conditions.
• Recovered iron phosphate (FePO4) and Li2CO3 were used to resynthesize LFP cathode materials via carbon-thermal reduction.

Main Results:

• Achieved 98.72% lithium leaching efficiency within 10 minutes using the H2SO4-H2O2 system.
• Successfully produced high-purity Li2CO3 from the leachate.
• Regenerated LFP cathode materials demonstrated potential for reuse.
• Preliminary economic analysis indicated a profit of USD 1.83 per kilogram of recycled LFP.
• The process utilizes minimal acid, with a low acid-to-lithium molar ratio (0.57), highlighting environmental advantages.

Conclusions:

• The developed method offers a green, efficient, and economically viable strategy for recycling spent LFP batteries.
• This approach significantly contributes to the development of a circular lithium battery economy.
• The process shows strong potential for industrial-scale application in battery recycling.