2D Trimetallic Metal-Organic Framework-Based Separator for Lithium-Sulfur Batteries with High Performance

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Lithium-sulfur batteries (LSBs) offer high energy density but suffer from polysulfide shuttling, limiting cycle stability.
• Polysulfide shuttling impedes commercial application of LSBs by causing capacity decay and anode corrosion.

Purpose of the Study:

• To develop a functional modification coating (FMC) for polypropylene (PP) separators to mitigate polysulfide shuttling in LSBs.
• To enhance the electrochemical performance and cycle stability of LSBs through advanced separator technology.

Main Methods:

• A functional modification coating (FMC) was created using 2D trimetallic metal-organic frameworks (2DT-MOFs) and amino-functionalized carbon nanotubes (CNT-NH2).
• The FMC was applied to a standard polypropylene (PP) separator for use in LSBs.
• Electrochemical performance, including discharge capacity and cycle stability, was evaluated.

Main Results:

• The FMC effectively adsorbed polysulfides and promoted their conversion, reducing anode corrosion.
• LSBs with the FMC@PP separator exhibited a 50% enhancement in initial discharge capacity (948 mAh g⁻¹ at 1C) compared to standard PP separators.
• The FMC@PP-based LSB maintained a specific capacity of 649 mAh g⁻¹ after 1500 cycles, demonstrating excellent cycle stability.

Conclusions:

• The developed FMC, integrating 2DT-MOFs and CNT-NH2, significantly improves LSB performance by suppressing polysulfide shuttling.
• This functionalized separator technology offers a promising pathway for the commercialization of high-performance and stable lithium-sulfur batteries.