Single‐Atom Vanadium Catalyst Boosting Reaction Kinetics of Polysulfides in Na–S Batteries

The practical application of the room‐temperature sodium–sulfur (RT Na–S) batteries is hindered by the insulated sulfur, the severe shuttle effect of sodium polysulfides, and insufficient polysulfide conversion. Herein, on the basis of first principles calculations, single‐atom vanadium anchored on a 3D nitrogen‐doped hierarchical porous carbon matrix (denoted as 3D‐PNCV) is designed and fabricated to enhance sulfur reactivity, and adsorption and catalytic conversion performance of sodium polysulfide. The 3D‐PNCV host with abundant and active V sites, hierarchical porous structure, high electrical conductivity, and strong chemical adsorption/conversion ability of V–N bonding can immobilize the polysulfides and promote reversibly catalytic conversion of polysulfides toward Na2S. Therefore, as‐fabricated RT Na–S batteries can achieve a high reversible capacity (445 mAh g−1 over 800 cycles at 5 A g−1) and excellent rate capability (224 mAh g−1 at 10 A g−1). The electrocatalysis mechanism of sodium polysulfides is further experimentally and theoretically revealed, which provides a new strategy to develop the highly stable RT Na–S batteries. Long‐life room‐temperature sodium–sulfur (RT Na–S) batteries are realized by the development of a single atom vanadium anchored on 3D nitrogen‐doped hierarchical porous carbon matrix (3D‐PNCV) as an ideal host in RT Na–S chemistry. Such host possesses the advantages of the abundant micro/mesoporous, highly reactive V single atom, which can restrain the polysulfides dissolution and in time catalyze the conversion of polysulfide into solid discharged products.