LiAlO₂-Modified Li Negative Electrode with Li₁₀GeP₂S₁₂ Electrolytes for Stable All-Solid-State Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal anodes offer high theoretical capacity but face challenges like dendrite formation and interface instability in solid-state batteries.
• Direct reactions between lithium metal and solid sulfide electrolytes (e.g., Li10GeP2S12) impede practical applications.
• Developing stable interfaces is crucial for advancing lithium metal-based all-solid-state batteries.

Purpose of the Study:

• To fabricate a stable interfacial layer for lithium metal anodes in solid-state batteries.
• To suppress lithium dendrite growth and mitigate interfacial reactions.
• To improve the cycling stability and energy efficiency of lithium metal batteries.

Main Methods:

• Fabrication of a lithium aluminum oxide (LiAlO2) interfacial layer on lithium metal using magnetic sputtering.
• Characterization of the LiAlO2 layer's properties as a Li+ ion conductor and electronic insulator.
• Assembly and testing of symmetric cells (Li@LiAlO2/Li10GeP2S12/Li@LiAlO2) and full cells (Li@LiAlO2/Li10GeP2S12/LiCoO2@LiNbO3).

Main Results:

• The LiAlO2 interfacial layer effectively suppressed lithium dendrite growth and reactions with the Li10GeP2S12 electrolyte.
• Symmetric cells demonstrated remarkable stability, operating for 3000 hours at 0.1 mA cm-2.
• Full cells exhibited a reversible capacity of 118 mAh g-1 with 96.6% energy efficiency after 50 cycles.
• The Li@LiAlO2 electrode retained 95% of its initial capacity after 800 cycles at 1.0 C.

Conclusions:

• The LiAlO2 interfacial layer is a promising strategy for stabilizing lithium metal anodes in solid-state batteries.
• This approach significantly enhances battery cycle life and energy efficiency.
• The findings pave the way for the development of safer and more robust high-energy-density lithium metal batteries.