Cathode Engineering Enables Robust Interface Contact for High-Performance All-Sulfide-Based Li-SeS₂ Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium-sulfur batteries offer high energy density and improved safety over liquid-based systems.
• Sulfur's insulating nature and low reactivity limit cathode performance in these batteries.
• Addressing sluggish kinetics and low utilization is crucial for advancing battery technology.

Purpose of the Study:

• To investigate selenium disulfide (SeS2) as a cathode active material for all-solid-state lithium-sulfur batteries.
• To enhance electronic conductivity and electrochemical performance compared to pure sulfur.
• To evaluate the potential of SeS2 composites for high-energy-density applications.

Main Methods:

• Fabrication of SeS2 composite cathodes using various strategies, including ball-milling with Li6PS5Cl and Ketjen Black (SeS2-BM@KB).
• Electrochemical characterization of battery cells, including cycling performance and capacity retention.
• Assessment of high-loading cells for areal capacity.

Main Results:

• The ball-milled SeS2/Li6PS5Cl/Ketjen Black composite cathode demonstrated excellent electrochemical performance.
• Cells achieved a reversible capacity of 673.5 mAh g-1 after 300 cycles at 1 A g-1 with 80% retention.
• High loading cells reached an impressive areal capacity of up to 14.43 mAh cm-2.

Conclusions:

• Selenium disulfide (SeS2) is a promising cathode material for all-solid-state lithium-sulfur batteries.
• Enhanced interaction at the three-phase interface in SeS2 composites improves performance.
• The developed SeS2 cathodes show potential for high-energy-density next-generation energy storage systems.