A fluorinated metal-organic framework-based quasi-solid electrolyte for stabilizing Li metal anodes.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal batteries (LMBs) are crucial for next-generation energy storage.
• Developing stable solid electrolytes is key to overcoming LMB limitations.
• Quasi-solid electrolytes (QSEs) offer a promising balance between safety and performance.

Purpose of the Study:

• To design and synthesize a novel fluorinated quasi-solid electrolyte (QSE) for LMBs.
• To investigate the QSE's electrochemical properties and interfacial behavior.
• To evaluate the long-term cycling performance of LMBs utilizing the developed QSE.

Main Methods:

• Synthesis of a fluorinated quasi-solid electrolyte.
• Electrochemical characterization including conductivity measurements.
• Assembly and testing of Li|QSE|LiFePO4 battery cells.
• Analysis of the solid electrolyte interphase (SEI) using advanced techniques.

Main Results:

• The QSE achieved a high ionic conductivity of 2.3 mS cm^-1.
• A LiF-rich solid electrolyte interface (SEI) was formed, enhancing Li anode reversibility.
• The Li|QSE|LiFePO4 batteries demonstrated 92.3% capacity retention after 1500 cycles.
• A high capacity of 45 mA h g^-1 was maintained at a 20C rate.

Conclusions:

• The fluorinated QSE is highly effective for stabilizing Li metal anodes.
• The developed electrolyte promotes excellent cycling stability and rate capability in LMBs.
• This QSE represents a significant advancement for safe and high-performance lithium metal batteries.