High-Performance Flexible Sulfur Cathodes with Robust Electrode Skeletons Built by a Hierarchical Self-Assembling...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur batteries offer high theoretical energy density but suffer from poor cathode stability.
• Developing cost-effective, robust hierarchical composite electrodes is crucial for practical applications.
• Uncontrollable component interactions hinder the creation of stable electrode structures.

Purpose of the Study:

• To design a self-assembling electrode slurry for stable lithium-sulfur battery cathodes.
• To create hierarchical porous structures with enhanced polysulfide trapping.
• To improve the electrochemical performance and cycle life of lithium-sulfur batteries.

Main Methods:

• Utilized a two-component polar binder system (polyacrylonitrile and polyvinylpyrrolidone) with carbon nanotubes.
• Employed water-vapor-induced phase separation for self-assembly of hierarchical porous structures.
• Fabricated composite sulfur cathodes with varying sulfur loadings.

Main Results:

• Achieved a robust and flexible electron-conductive network with hierarchical ion-transport channels.
• Demonstrated stable specific capacity of 485 mAh g⁻¹ at 3.74 mA cm⁻² after 1000 cycles with 4.53 mg cm⁻² sulfur loading.
• Obtained a high capacity of 600 mAh g⁻¹ at 0.72 mA cm⁻² for 78 cycles with 14.5 mg cm⁻² sulfur loading in a pouch cell.

Conclusions:

• The self-assembling slurry strategy effectively creates stable hierarchical structures for lithium-sulfur cathodes.
• The developed electrodes exhibit excellent electrochemical performance and cycle stability.
• This approach offers a promising pathway for high-performance, flexible lithium-sulfur batteries.