High-Performance Quasi-Solid-State Lithium-Sulfur Battery with a Controllably Solidified Cathode-Electrolyte...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries are a promising beyond lithium-ion energy storage technology.
• Polysulfide dissolution and shuttle in liquid electrolytes cause rapid electrochemical failure of S cathodes.
• Gel polymer electrolytes prevent shuttle but reduce polysulfide solubility, hindering performance.

Purpose of the Study:

• To address the limitations of gel polymer electrolytes in Li-S batteries.
• To improve polysulfide conversion kinetics and interfacial charge migration.
• To enhance the overall capacity, cycle life, and rate performance of Li-S batteries.

Main Methods:

• Utilized thioacetamide as a cathode additive.
• Investigated the effect of thioacetamide on interfacial polymerization and polysulfide solubility.
• Analyzed the resulting cathode-electrolyte interface structure and battery performance.

Main Results:

• Thioacetamide inhibited interfacial polymerization and enhanced polysulfide and Li2S dissolution.
• A liquid, sulfide-soluble electrolyte layer was preserved at the cathode/electrolyte interface.
• The Li-S battery demonstrated high reversible capacity, long cycle life, and good rate performance.

Conclusions:

• Thioacetamide effectively mitigates interfacial issues in Li-S batteries without additional catalysts.
• The strategy preserves electrolyte liquidity, improving charge transfer and battery performance.
• Controllably solidified interfaces show promise for next-generation energy storage applications.