High-performance expanded graphite regenerated from spent lithium-ion batteries by integrated oxidation and...

Area of Science:

• Materials Science
• Electrochemistry
• Environmental Science

Background:

• Spent lithium-ion batteries (LIBs) recycling primarily focuses on valuable cathode metals, neglecting waste graphite anodes.
• Waste graphite anodes pose both pollution risks and represent untapped potential for resource recovery.

Purpose of the Study:

• To develop an efficient, integrated method for preparing high-performance expanded graphite (EG) anode material from waste LIB graphite.
• To demonstrate the value-added recycling of graphite anodes, enhancing their electrochemical properties.

Main Methods:

• A one-step oxidation and purification process using potassium permanganate in a sulfur-phosphorus mixed acid system.
• Controlled regulation of oxidizability to achieve simultaneous graphite expansion and impurity removal.

Main Results:

• Successful preparation of EG from waste LIB graphite with excellent electrochemical performance.
• Achieved a reversible capacity of 435.8 mAh·g^-1 at 0.1C and retained 370 mAh·g^-1 at 1C after 1000 cycles.
• The developed EG outperformed pristine commercial graphite.

Conclusions:

• The proposed method offers an integrated approach for purifying and upgrading waste graphite into high-performance anode material.
• This strategy reduces production costs and environmental impact, providing a sustainable solution for LIB recycling.
• The regenerated EG can meet the growing demand for advanced anode materials in future LIB applications.