High-Performance Lithium-Sulfur Batteries with a Self-Assembled Multiwall Carbon Nanotube Interlayer and a Robust...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Elemental sulfur cathodes offer high charge capacity but suffer from poor electrical conductivity, limiting their electrochemical utilization.
• Existing solutions using multiwall carbon nanotube (MWCNT) paper interlayers show promise but can be improved.
• Dissolved polysulfides contribute to capacity fading in lithium-sulfur (Li-S) batteries.

Purpose of the Study:

• To develop an advanced self-assembled MWCNT interlayer for enhanced Li-S battery performance.
• To overcome the conductivity limitations of elemental sulfur cathodes.
• To improve the trapping and reutilization of migrating polysulfides.

Main Methods:

• Fabrication of a self-assembled MWCNT interlayer using a facile, low-cost process.
• Integration of the MWCNT interlayer into Li-S cells with a high sulfur loading (3 mg cm⁻²).
• Electrochemical testing including rate capability and cycling stability measurements.

Main Results:

• The self-assembled MWCNT interlayer facilitated excellent interfacial contact and fast ion/electron transport.
• Li-S cells achieved a high initial discharge specific capacity of 1112 mAh g⁻¹ at 0.1 C.
• Cells retained 95.8% of capacity after 100 cycles at 0.5 C, demonstrating superior cycling stability.

Conclusions:

• The self-assembled MWCNT interlayer effectively addresses the conductivity and polysulfide issues in Li-S batteries.
• This approach significantly enhances the electrochemical performance and commercialization potential of Li-S batteries.
• The facile fabrication process makes this a cost-effective solution for advanced energy storage.