Paving the way for using Li₂S batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density.
• Performance limitations of Li-S batteries are often linked to electrolyte composition and polysulfide shuttling.

Purpose of the Study:

• To develop a novel lithium-sulfur battery with improved electrochemical performance.
• To investigate the effect of electrolyte composition on Li2S cathode activation and stability.

Main Methods:

• Fabrication of a Li-S battery utilizing Li2S cathode, lithium metal anode, and a polysulfide-based electrolyte.
• Electrochemical testing to evaluate performance with conventional and modified electrolytes.

Main Results:

• Conventional electrolytes (LiTFSI in DME/DOL) resulted in poor kinetics, cycling, and capacity retention.
• Modified electrolytes with small amounts of polysulfides and a shuttle inhibitor activated the Li2S cathode.
• Achieved over 1000 mAh/g capacity with good cycle life using the modified electrolyte.

Conclusions:

• Electrolyte engineering is crucial for enhancing Li-S battery performance.
• The addition of polysulfides and shuttle inhibitors effectively mitigates performance issues in Li-S cells.
• The developed Li-S battery demonstrates promising potential for high-energy storage applications.