High Sulfur Content Material with Stable Cycling in Lithium-Sulfur Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density but suffer from polysulfide shuttle.
• Developing stable cathode materials is crucial for improving Li-S battery performance.

Purpose of the Study:

• To design and demonstrate a novel crosslinked disulfide cathode material for Li-S cells.
• To maximize theoretical capacity and inhibit polysulfide formation.

Main Methods:

• Synthesis of a crosslinked disulfide system with a 1:1 sulfur:carbon ratio.
• Electrochemical cycling and capacity retention testing over 200 cycles.
• Raman spectroscopy to confirm the discharge/charge mechanism.

Main Results:

• The material achieved a theoretical capacity of 609 mAh g⁻¹.
• Cells exhibited stable cycling with 98% capacity retention after 100 cycles.
• Near 100% Coulombic efficiency indicated suppressed polysulfide shuttle.

Conclusions:

• The novel disulfide cathode material effectively suppresses polysulfide shuttle.
• The molecular design enables stable, long-term cycling and high capacity retention in Li-S cells.