Enhancing Lithium–Sulfur Batteries Performance with Mn Atomic Clusters Modified Separator via Promoting Polysulfide Conversion

The shuttle effect and sluggish conversion kinetics of lithium polysulfide (LiPS) are key challenges that constrain the large-scale application of lithium sulfur batteries (LSBs). To tackle these challenges, a facile ligand-mediated pyrolysis strategy was employed to fabricate N-doped activated carbon modified with manganese clusters (denoted as Mnx@NAC). The Mnx@NAC catalyst provides abundant active sites for the strong adsorption of polysulfides while simultaneously reducing the Gibbs free energy for polysulfide redox reactions, thus effectively suppressing LiPS shuttling and enhancing battery performance. Consequently, LSBs with Mnx@NAC-modified separator exhibit a superior rate performance of 550 mA h g⁻¹ at 5 C and a reversible capacity of 675 mA h g⁻¹ after 300 cycles at 1 C. Even with a sulfur loading of 4.6 mg cm⁻², the LSBs retain a stable capacity of 612 mA h g⁻¹ after 100 cycles. The catalyst design strategy presented here offers a facile route to develop modified separators for high-performance Li-S batteries.