A Large-Area Uniform Three-Dimensional Covalent Organic Framework Membrane for Stabilizing Li-Metal Electrodes via...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Covalent organic frameworks (COFs) show potential for ion conduction in batteries.
• Rigid COFs are difficult to process into membranes, and composites suffer from conductivity loss.
• Existing COF materials face challenges in membrane fabrication and ionic pathway continuity.

Purpose of the Study:

• To develop a phase-continuous 3D-COF membrane for enhanced battery performance.
• To overcome limitations of traditional COF processing and composite membranes.
• To create a large-scale COF membrane (15 cm × 25 cm) for practical battery applications.

Main Methods:

• Fabrication of a 3D-COF membrane using in-situ interfacial engineering.
• Characterization of the COF membrane's topology (non-interpenetrating dia) and ionic pathways.
• Evaluation of the membrane's performance in Li|NMC622 batteries.

Main Results:

• The 3D-COF membrane exhibited 3D continuous ionic pathways at the molecular level.
• Hydroxyl and imine groups facilitated Li+-solvation cages and Li-solvate conversion.
• The membrane effectively inhibited Li-dendrites and parasitic reactions, showing good cycling performance.

Conclusions:

• The developed 3D-COF membrane offers a promising solution for high-performance batteries.
• In-situ fabrication and unique topology enable continuous ion transport and dendrite suppression.
• This work advances the application of COFs in energy storage devices.