A Highly Reversible, Dendrite-Free Lithium Metal Anode Enabled by a Lithium-Fluoride-Enriched Interphase

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Metallic lithium is a promising anode for next-generation lithium-ion batteries.
• Lithium dendrite growth causes safety concerns and reduces battery performance (low coulombic efficiency, short cycle life).

Purpose of the Study:

• To suppress lithium dendrite growth in metallic lithium anodes.
• To improve the coulombic efficiency and cycle life of lithium metal batteries.

Main Methods:

• Forming a lithium fluoride (LiF)-enriched solid electrolyte interphase (SEI) on mesocarbon microbeads (MCMB-F) through lithiation.
• Investigating the effect of the LiF-enriched SEI on lithium metal planar growth and dendrite suppression.
• Testing LiFePO4//Li@MCMB-F full cells.

Main Results:

• A LiF-enriched SEI effectively promotes planar lithium growth and prevents dendrite formation.
• Achieved high coulombic efficiency (>99.2%) for Li plating/stripping at 1.2 mAh cm⁻² in FEC-based electrolyte within 25 cycles.
• LiFePO4//Li@MCMB-F cells demonstrated stable cycling at 2.4 mAh cm⁻² for 110 cycles with negligible capacity decay (0.01% per cycle).

Conclusions:

• Surface fluorination of MCMB anodes creates a robust LiF-enriched SEI that suppresses lithium dendrites.
• This strategy significantly enhances the safety and cycle life of lithium metal batteries.
• The developed anode material is suitable for high-performance lithium-ion batteries.