Stable Lithium Metal Anode Enabled by a Lithiophilic and Electron/Ion Conductive Framework

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Lithium metal anodes offer high capacity but suffer from low Coulombic efficiency, volume changes, and dendrite growth, hindering practical battery applications.
• Developing stable and efficient lithium metal anodes is crucial for next-generation high-energy-density batteries.

Purpose of the Study:

• To design and prepare a highly stable three-dimensional (3D) lithium metal anode.
• To improve the electrochemical performance and safety of lithium metal batteries.

Main Methods:

• Fabrication of a 3D structured lithium metal anode via *in situ* reaction between lithium metal and aluminum nitride (AlN).
• Characterization of the anode's structure, composition, and electrochemical properties.
• Assembly and testing of full cells using LiFePO4 and sulfurized polyacrylonitrile (S@pPAN) cathodes.

Main Results:

• Simultaneous formation and homogeneous distribution of highly Li+ conductive Li3N and lithiophilic LiAl alloy within the 3D framework.
• Enhanced electron/ion mixed conductivity and interfacial area, suppressing volume changes and improving electrode kinetics.
• Avoidance of dendritic lithium deposition due to lithiophilic LiAl alloy and uniform Li+ flux, leading to exceptional electrochemical reversibility in various electrolytes.
• Stable and long-term cycling performance in full cells with LiFePO4 and S@pPAN cathodes.

Conclusions:

• The proposed strategy for fabricating 3D structured lithium metal anodes effectively addresses key challenges like dendrite growth and volume expansion.
• The developed anode demonstrates superior electrochemical reversibility and cycling stability, paving the way for practical lithium metal battery applications.