Porous Ionic Network/CNT Composite Separator as a Polysulfide Snaring Shield for High Performance Lithium-Sulfur...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density.
• Polysulfide shuttle effect leads to rapid capacity decay in Li-S batteries.
• Effective strategies are needed to suppress polysulfide migration.

Purpose of the Study:

• To develop a novel separator for Li-S batteries.
• To mitigate the polysulfide shuttle effect using electrostatic adsorption.
• To enhance the rate performance and cycling stability of Li-S batteries.

Main Methods:

• Fabrication of a cross-linked polyimidazolium (PIN) modified carbon nanotube (CNT) separator.
• Coating the PIN/CNT composite onto a commercial polypropylene membrane via vacuum filtration.
• Characterization of the separator's performance in Li-S battery cells.

Main Results:

• The PIN/CNT separator effectively snared soluble polysulfides via polar and electrostatic interactions.
• Suppression of polysulfide migration significantly improved Li-S battery performance.
• The PIN/CNT-coated separator demonstrated a 1.3-fold increase in initial capacity compared to the control.

Conclusions:

• The electrostatic adsorption strategy using PIN/CNT separators is effective in suppressing polysulfide shuttle.
• This approach enhances the cycling life and rate capability of Li-S batteries.
• The developed separator shows promise for advanced energy storage applications.