Polysulfide Rejection Strategy in Lithium-Sulfur Batteries Using an Ion-Conducting Gel-Polymer Interlayer Membrane

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur batteries (LiSBs) offer high energy density but suffer from polysulfide dissolution, hindering commercialization.
• Polysulfide migration causes the shuttle effect, degrading battery performance and lifespan.

Purpose of the Study:

• To develop an ion-conducting gel-polymer membrane (IC-GPM) interlayer to suppress polysulfide migration in LiSBs.
• To enhance the electrochemical performance and durability of LiSBs through electrostatic rejection and trapping of polysulfides.

Main Methods:

• Preparation of a lithium salt and ionic liquid (SIL) solution-impregnated IC-GPM interlayer (IC-GPM70).
• Utilizing anionic groups for lithium-ion conduction and polysulfide rejection, and cationic groups for polysulfide trapping.
• Electrochemical testing of LiSBs with and without the IC-GPM70 interlayer.

Main Results:

• The IC-GPM70 interlayer exhibited high lithium-ion conductivity (2.58 × 10^-3 S cm^-1) and thermal stability.
• Suppression of the polysulfide shuttle effect led to significantly improved cycling stability (1200 cycles) and rate performance.
• LiSBs with the interlayer demonstrated enhanced structural integrity and overall durability.

Conclusions:

• The developed SIL-based IC-GPM70 interlayer effectively prevents polysulfide issues in LiSBs.
• This strategy enhances LiSB performance, making them a competitive alternative to lithium-ion batteries.
• The interlayer technology holds promise for advancing next-generation battery technologies.