A lithium anode protection guided highly-stable lithium-sulfur battery

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density but suffer from the polysulfide shuttle effect.
• The shuttle effect leads to capacity degradation and low coulombic efficiency, limiting practical applications.
• Anode protection is crucial for stabilizing Li-S battery performance.

Purpose of the Study:

• To develop an effective anode protection strategy for Li-S batteries.
• To suppress the polysulfide shuttle effect using an in situ fabricated protection layer.
• To evaluate the electrochemical performance of Li-S cells with protected anodes.

Main Methods:

• Fabrication of a lithium nitride (Li3N) protection layer on the lithium anode surface via an in situ method.
• Assembly of Li-S coin cells with simple sulfur cathodes (2.5-3 mg cm(-2) sulfur loading).
• Electrochemical testing, including cycling performance and coulombic efficiency measurements in an electrolyte without LiNO3.

Main Results:

• The in situ Li3N layer effectively suppressed the shuttle effect.
• The protected Li anode demonstrated excellent stability over 500 cycles.
• A high discharge capacity of 773 mA h g(-1) was retained after 500 cycles.
• An average coulombic efficiency of 92.3% was achieved without LiNO3 in the electrolyte.

Conclusions:

• In situ fabrication of a Li3N protection layer is a viable strategy for anode protection in Li-S batteries.
• The Li3N layer significantly enhances the cycling stability and coulombic efficiency of Li-S cells.
• This approach shows promise for developing high-performance and long-lasting Li-S energy storage systems.