Microwave-Assisted Expanded Graphite as a Long Cyclic Cathode for the Lithium Dual-Ion Battery

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal anodes offer high theoretical capacity but suffer from safety issues and capacity fade.
• Developing stable and high-performance alternatives is crucial for advanced energy storage devices.

Purpose of the Study:

• To develop a novel lithium-expanded graphite dual-ion battery (Li-EG DIB) for improved energy storage.
• To optimize the synthesis of expanded graphite (EG) using microwave (MW) irradiation for enhanced electrochemical performance.

Main Methods:

• Synthesized expanded graphite (EG) via microwave irradiation for varying durations (15-60 s).
• Fabricated Li-EG DIBs using lithium metal anodes and MW-EG cathodes.
• Characterized MW-EG materials using XRD, Raman spectroscopy, and FT-IR.
• Evaluated electrochemical performance, including capacity, cycling stability, and rate capability.

Main Results:

• Microwave-expanded graphite synthesized at 45 seconds (EG-45) exhibited optimal properties.
• The Li-EG-45 DIB achieved a charge capacity of 20.3 mAh g⁻¹ after 500 cycles at 0.05 A g⁻¹ within a 2-5 V window.
• The EG-45 electrode demonstrated approximately 100% capacity retention even after rate testing, indicating superior stability.

Conclusions:

• Optimized microwave-assisted synthesis of expanded graphite yields a high-performance cathode material.
• The developed Li-EG DIB shows significant potential for safe and stable energy storage applications.
• The EG-45 cathode offers excellent capacity retention and cycling life, addressing limitations of traditional lithium metal anodes.