In Situ Polymer-Integrated Metal-Organic Framework for Solid-State Electrolyte Membrane.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid-state lithium metal batteries offer improved safety and energy density over liquid electrolyte systems.
• Developing efficient solid-state electrolytes with high ionic conductivity and stability is crucial for practical applications.
• Existing solid-state electrolytes face challenges in interfacial compatibility and ion transport.

Purpose of the Study:

• To develop a novel composite solid-state electrolyte membrane for lithium metal batteries.
• To enhance ionic conductivity, electrochemical stability, and interfacial properties.
• To address the limitations of current solid-state electrolyte technologies.

Main Methods:

• Fabrication of a composite electrolyte membrane by integrating metal-organic frameworks (MOFs) with in situ-formed polymer chains.
• Initiation of in situ polymerization of N,N-dimethylacrylamide using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) within MOFs.
• Characterization of ionic conductivity, Li+ transference number, electrochemical stability window, and interfacial properties.

Main Results:

• Achieved high room-temperature ionic conductivity (>10⁻⁴ S·cm⁻¹).
• Demonstrated a high Li+ transference number (0.77) and a broad electrochemical stability window (up to 5.67 V).
• Exhibited excellent interfacial compatibility with lithium metal, effectively inhibiting dendrite growth, and enabling high capacity (124.2 mAh·g⁻¹ at 1.0 C) and Coulombic efficiency (99.5%) in lithium metal batteries.

Conclusions:

• The MOF-polymer composite electrolyte membrane provides efficient Li+ transport pathways and restricts anion mobility.
• The developed electrolyte exhibits superior performance characteristics for solid-state lithium metal batteries.
• This work presents a promising strategy for designing advanced solid-state electrolytes for next-generation energy storage devices.