A Novel Zwitterionic Ionic Liquid-Based Electrolyte for More Efficient and Safer Lithium-Sulfur Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries face challenges from polysulfide shuttle and electrolyte flammability.
• Current solutions often compromise electrochemical performance.

Purpose of the Study:

• To develop a novel electrolyte component to address Li-S battery limitations.
• To improve both safety and electrochemical performance simultaneously.

Main Methods:

• Synthesis and characterization of a zwitterionic ionic liquid (TLTFSI).
• Electrolyte formulation and testing in Li-S battery configurations.
• Electrochemical performance evaluation (capacity, rate capability, cycle life).

Main Results:

• TLTFSI exhibits high ionic conductivity (3.7 × 10⁻³ S cm⁻¹), a wide electrochemical window (1.51–4.82 V), and high thermal stability (275 °C).
• TLTFSI-based electrolytes are nonflammable and demonstrate superior capacity, rate capability, and cycle life compared to conventional organic electrolytes.
• Improved performance is linked to suppressed polysulfide dissolution and enhanced lithium anode compatibility.

Conclusions:

• Zwitterionic ionic liquids are effective in enhancing Li-S battery performance and safety.
• TLTFSI offers a promising solution for overcoming critical obstacles in Li-S battery development.