A Carbon-Cotton Cathode with Ultrahigh-Loading Capability for Statically and Dynamically Stable Lithium-Sulfur...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sulfur cathodes offer high theoretical capacity via conversion reactions, distinct from lithium-ion battery insertion mechanisms.
• Achieving high loading and stability in lithium-sulfur (Li-S) batteries requires custom electrode material design.
• Carbon materials with hierarchical porosity are explored for advanced battery applications.

Purpose of the Study:

• To introduce carbon cotton as an electrode-containment material for enhancing lithium-sulfur (Li-S) battery stability.
• To investigate the electrochemical performance of Li-S batteries utilizing carbon cotton cathodes.
• To achieve high sulfur loading and content while maintaining electrochemical utilization and stability.

Main Methods:

• Synthesis of carbon cotton with hierarchical macro-/microporous architecture.
• Characterization of carbon cotton's surface area (805 m² g⁻¹) and microporosity (557 m² g⁻¹).
• Fabrication and electrochemical testing of high-loading Li-S battery cathodes using carbon cotton.

Main Results:

• Carbon cotton cathodes demonstrated enhanced cycle stability with 70% capacity retention after 100 cycles.
• Improved cell-storage stability was observed, with >93% static capacity retention and a low self-discharge rate (0.12% per day over 60 days).
• Record sulfur loading (61.4 mg cm⁻²) and sulfur content (80 wt%) were achieved, leading to superior areal, volumetric, and gravimetric capacities.

Conclusions:

• Carbon cotton serves as an effective electrode-containment material for high-performance Li-S batteries.
• The hierarchical porous structure of carbon cotton facilitates high active material loading and efficient redox chemistry.
• The developed Li-S batteries exhibit remarkable stability and energy density, paving the way for advanced energy storage.