MOF-Ionic Liquid Structured Polymer Electrolytes with Multi-Channel Ion Transport Pathways for Wide-Temperature...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Composite polymer electrolytes (CPEs) with ionic liquids (ILs) show promise for solid-state lithium metal batteries.
• A key challenge is balancing mechanical strength and ionic conductivity over a broad temperature range.

Purpose of the Study:

• To develop a novel CPE architecture that decouples mechanical robustness and ionic conductivity.
• To enhance the performance of solid-state lithium batteries for wide-temperature applications.

Main Methods:

• Designed a poly(ethylene oxide)-based CPE incorporating amino-functionalized metal-organic framework (MOF) nanoparticles.
• Utilized MOFs to encapsulate ILs within electrospun membranes, creating multi-channel ion pathways.
• Conducted combined experimental and computational studies to analyze ion transport mechanisms and interfacial properties.

Main Results:

• The MOF-enhanced CPE demonstrated high ionic conductivity and structural stability from -10 to 120 °C.
• Achieved fast Li⁺ hopping at interfaces and boosted bulk ion transport via MOF-confined ILs.
• Optimized CPEs facilitated stable solid and cathode electrolyte interphases, leading to excellent LiFePO₄||Li cell cyclability (96.8% capacity retention after 1000 cycles).

Conclusions:

• The novel MOF-based CPE architecture successfully decouples mechanical and electrochemical properties.
• This strategy enables high performance and stability in solid-state lithium batteries across a wide temperature range.
• The findings present a new approach for designing advanced polymer electrolytes for next-generation batteries.