AlF₃-Decorated 3D Graphene Aerogel as a Multifunctional Host Material for High-Performance Lithium Metal Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal anodes face challenges like infinite volume change, lithium dendrite growth, and unstable solid electrolyte interphase (SEI) during cycling.
• These issues limit the performance and safety of high-energy-density lithium metal batteries.

Purpose of the Study:

• To design a novel composite lithium anode host material to overcome the limitations of traditional lithium metal anodes.
• To enhance the stability and cycling performance of lithium metal anodes for advanced battery applications.

Main Methods:

• Fabrication of an AlF3-decorated three-dimensional graphene aerogel (AlF3/GA) host material via thermal infusion.
• Preparation of a composite lithium anode (AlF3/GA/Li) by infusing molten lithium into the AlF3/GA host.
• Electrochemical testing of AlF3/GA/Li symmetric cells and full cells with high-sulfur-loading cathodes.

Main Results:

• The AlF3/GA/Li anode exhibited a stable LiF-rich solid electrolyte interphase (SEI) and a lithiophilic Li-Al alloy.
• The composite anode demonstrated significantly reduced nucleation overpotential and suppressed lithium dendrite growth.
• Symmetric cells maintained a low overpotential (19 mV) after 800 hours of cycling at 2 mA cm-2.
• Full cells achieved an ultrahigh initial discharge specific energy of 836.62 Wh kg-1.

Conclusions:

• The AlF3/GA host effectively accommodates volume changes and promotes uniform lithium deposition.
• The synergistic structural and interfacial optimization provides a viable strategy for high-energy-density and long-life lithium metal batteries.