Nonmetallic-Bonding Fe–Mn Diatomic Pairs Anchored on Hollow Carbonaceous Nanodisks for High-Performance Li–S Battery

The issues of polysulfide shuttling and lethargic sulfur redox reaction (SROR) kinetics are the toughest obstacles of lithium–sulfur (Li–S) battery. Herein, integrating the merits of increased density of metal sites and synergistic catalytic effect, a unique single-atom catalyst (SAC) with nonmetallic-bonding Fe–Mn diatomic pairs anchored on hollow nitrogen-doped carbonaceous nanodisk (denoted as FeMnDA@NC) is successfully constructed and well characterized by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy, X-ray absorption spectroscopy, etc. Density functional theory calculation indicates that the Fe–Mn diatomic pairs can effectively inhibit the shuttle effect by enhancing the adsorption ability retarding the polysulfide migration and accelerate the SROR kinetics. As a result, the Li–S battery assembled with FeMnDA@NC modified separator possesses an excellent electrochemical performance with ultrahigh specific capacities of 1419 mAh g⁻¹ at 0.1 C and 885 mAh g⁻¹ at 3.0 C, respectively. An outstanding specific capacity of 1165 mAh g⁻¹ is achieved at 1.0 C and maintains at 731 mAh g⁻¹ after 700 cycles. Notably, the assembled Li–S battery with a high sulfur loading of 5.35 mg cm⁻² harvests a practical areal capacity of 5.70 mAh cm⁻² at 0.2 C. A new perspective is offered here to construct advanced SACs suitable for the Li–S battery.