Topological Li-SbF₃@Cu Alloying Anode for High-Energy-Density Li Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Ultrathin lithium (Li) alloying anodes (≤ 50 µm) are critical for rechargeable Li metal batteries due to challenges with pure Li anodes.
• High Li utilization is essential for practical, high-energy-density applications.

Purpose of the Study:

• To develop a thickness-controllable (≈5.5-30 µm) Li-SbF3@Cu anode.
• To enhance Li deposition/dissolution and Li/electrolyte interface evolution for high-energy-density Li metal batteries.

Main Methods:

• Fabrication of a topological Li-SbF3@Cu anode with embedded dual Li-based alloys (Li3Sb and Li-Cu) and an outer LiF-rich layer.
• Electrochemical testing of symmetric cells and full cells with LiCoO2 cathodes.

Main Results:

• The Li-SbF3@Cu anode demonstrated stable cycling over 1200 h at 1 mA cm-2/1 mAh cm-2.
• Achieved an ultrahigh discharge/charge depth of 53.6% at 2 mA cm-2/3 mAh cm-2.
• A full cell delivered an energy density of 394.5 Wh kg-1 with impressive cycling reversibility at a low N/P ratio of 1.5.

Conclusions:

• The synergistic effect of the LiF-rich layer, lithiophilic Li3Sb sites, and Li-Cu skeletons effectively regulates Li deposition and interface evolution.
• The developed anode offers a promising pathway for industrial application of high-Li-utilization alloying anodes in practical high-energy-density Li metal batteries.