Enhanced Performance of a Lithium-Sulfur Battery Using a Carbonate-Based Electrolyte

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high energy density but face challenges with lithium anode dendrite formation and sulfur cathode instability.
• These issues limit the practical application and cycle efficiency of current Li-S battery designs.

Purpose of the Study:

• To develop a novel electrolyte for lithium-sulfur batteries that addresses lithium anode instability and enhances sulfur cathode performance.
• To improve the overall electrochemical performance, cycle life, and practical applicability of Li-S batteries.

Main Methods:

• Design and synthesis of a novel electrolyte: 1 m LiODFB/EC-DMC-FEC.
• Electrochemical testing of lithium|lithium cells to evaluate anode stability and Coulombic efficiency.
• Performance evaluation of Li-S batteries, including capacity, cycle retention, and stability at elevated temperatures.

Main Results:

• The novel electrolyte enabled stable cycling of lithium|lithium cells for over 2000 hours with an average Coulombic efficiency of 98.8%.
• The Li-S battery demonstrated a reversible capacity of ~1400 mAh/g sulfur, retaining 89% over 1100 cycles at 1 C.
• High capacity (~1100 mAh/g sulfur) was maintained at 10 C, with excellent cycle stability at 60°C and no self-discharge.

Conclusions:

• The developed LiODFB/EC-DMC-FEC electrolyte effectively suppresses lithium dendrite formation and stabilizes the sulfur cathode.
• This electrolyte significantly enhances the electrochemical performance and cycle stability of lithium-sulfur batteries.
• The findings suggest a promising pathway for the practical realization of high-energy-density lithium-sulfur batteries.