A Universal Solid Reaction Enabling Nanosized Li₂S in an Amorphous Matrix for All-Solid-State Li-S Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium sulfide (Li₂S) is crucial for all-solid-state lithium-sulfur (Li-S) batteries.
• Challenges include low conductivity and poor active material utilization.

Purpose of the Study:

• To design a new cathode material for improved Li-S battery performance.
• To address conductivity and utilization issues in Li₂S cathodes.

Main Methods:

• Developed a cathode with nanosized Li₂S embedded in an amorphous LiFeS₂ matrix (92Li₂S@8LiFeS₂).

Main Results:

• The 92Li₂S@8LiFeS₂ cathode demonstrated excellent cycling stability with >99% capacity retention after 320 cycles.
• Achieved an areal capacity of 13.2 mAh/cm² with 48% active material content and 19.1 mg/cm² mass loading.

Conclusions:

• The LiFeS₂ matrix enhances electronic/ionic conductivity and provides a catalytic effect.
• Nanosized Li₂S shortens ion/electron transport distances, improving battery performance.