Hydrogen-Bonded Organic Framework with Desolventization and Lithium-Rich Sites for High-Performance Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Organic Chemistry

Background:

• Managing lithium ion (Li+) migration and electrolyte-electrode interface reactions is critical for high-performance lithium metal batteries (LMBs).
• Existing strategies often struggle with interfacial instability and side reactions, limiting battery lifespan.

Purpose of the Study:

• To introduce a novel two-dimensional hydrogen-bonded organic framework (HOF) for stabilizing lithium metal anodes (LMAs).
• To tailor the electronic structure and solvation chemistry of electrolytes and improve the LMA interface.

Main Methods:

• Synthesis and characterization of a 2D HOF with multi-site H-bonding and lithiophilic sites.
• Modification of the electrolyte-electrode interface using the HOF.
• In situ and ex situ characterizations to analyze interfacial properties and battery performance.

Main Results:

• The HOF's lithiophilic sites (C═O, C═N) coordinate with Li+, optimizing electronic structure and reducing desolvation energy.
• Hydrogen bonding in the HOF anchors -NH2 to LiTFSI, mitigating adverse reactions and mechanical stress.
• HOF-modified batteries demonstrated ultra-long cycling (11,000 hours) and stable voltage at 3 mA cm-2.

Conclusions:

• The HOF effectively stabilizes the LMA interface by synergistic effects of hydrogen bonding and lithiophilic sites.
• This approach offers a new strategy for designing artificial interfacial layers for advanced lithium metal batteries.
• The developed HOF significantly enhances the cycling performance and stability of lithium metal batteries.