A 3D mixed ion-electron conducting framework for dendrite-free lithium metal anodes

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Lithium metal batteries (LMBs) are promising for high energy density storage.
• Dendrite growth and volume expansion in lithium metal anodes hinder practical application of LMBs.
• A 3D framework can regulate lithium plating/stripping and improve anode stability.

Purpose of the Study:

• To develop a 3D mixed ion-electron conducting (MIEC) framework for lithium metal anodes.
• To address dendrite growth and volume expansion challenges in LMBs.
• To enhance the electrochemical performance and cycling stability of lithium metal anodes.

Main Methods:

• Fabrication of a 3D MIEC framework by conformally coating carbon nanotubes (CNTs) onto Li$_{0.5}$La$_{0.5}$TiO$_{3}$ (LLTO) particles.
• Electrochemical characterization of the LLTO@CNT anode in a half-cell configuration.
• Evaluation of coulombic efficiency, cycling stability, and lifespan under specific current densities.

Main Results:

• The LLTO@CNT anode exhibited a high coulombic efficiency of 99.24% over 400 cycles at 1 mA cm$^{-2}$.
• The synergistic effect between LLTO's lithiophilicity and CNTs' conductivity ensured uniform lithium deposition.
• The 3D framework effectively mitigated volume changes and suppressed dendrite formation.
• Excellent cycling stability and a prolonged lifespan were achieved for the LLTO@CNT anode.

Conclusions:

• The developed 3D MIEC framework (LLTO@CNT) is a promising solution for stable lithium metal anodes in LMBs.
• This approach effectively addresses critical challenges of dendrite growth and volume expansion.
• The enhanced electrochemical performance and longevity pave the way for practical applications of high-energy-density batteries.