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

Lithium-sulfur batteries (LSBs) have become one of the focuses of sustainable energy materials because of their high energy density and environmentally friendly characteristics. However, the problem of polysulfide shuttling during the battery cycle seriously affects its cycle stability, which makes its commercial application a huge challenge. Here, a polypropylene (PP) separator with a functional modification coating (FMC) composed of 2D trimetallic metal-organic frameworks (2DT-MOFs) and amino-functionalized carbon nanotubes (CNT─NH₂) for LSBs is presented. This 2DT-MOF can effectively adsorb the polysulfides (PSs) and promote their rapid conversion, which is beneficial to reduce their penetration across the separator to corrode the anode. The high conductivity and adsorption capacity toward the PSs of CNT─NH₂ also play a significant positive role in this process. The obtained FMC@PP-based LSB achieves an initial discharge capacity of 948 mAh g⁻¹ at 1C, a 50% enhancement over the PP-based one, and maintains a specific capacity of 649 mAh g⁻¹ after 1500 cycles.