Coupling Antimony Nanoclusters and Tungsten Nitride With Strong Interaction as a Remarkable Bidirectional Electrocatalyst Toward Robust Lithium-Sulfur Batteries.

The pursuit of high-efficiency electrocatalysts that are capable of accelerating the sluggish redox reaction kinetics of lithium polysulfides (LiPSs) still remains a grand challenge in lithium-sulfur (Li─S) batteries. Herein, a novel electrocatalyst with ultrasmall antimony nanoclusters (Sb NCs) anchored on tungsten nitride (W5N4) support (denoted as Sb NCs/W5N4) with strong metal-support interaction is elaborately designed. Experimental results and theoretical calculations reveal that the Sb NCs/W5N4 electrocatalyst showcases strong chemical adsorption capability and excellent catalytic activity toward LiPSs. Benefiting from the multiple advantages, the Sb NCs/W5N4 modified separators can efficiently accelerate the LiPS conversion, suppress the shuttle effect, facilitate the lithium ion transportation, and prevent lithium dendrite growth. Impressively, significantly improved Li─S battery performances are achieved, including high specific discharge capacity (1439.4 mAh g-1 at 0.1 C), remarkable rate capability (763.1 mAh g-1 at 5 C), and stable long-term cycling stability (0.058% capacity decay per cycle at 1 C over 500 cycles). Furthermore, a satisfactory areal capacity of 4.75 mAh cm-2 is obtained at high sulfur loading (6.1 mg cm‒2) and lean electrolyte (8.2 µL mg-1). This work presents an important perspective for the rational development of high-efficiency electrocatalysts toward robust Li─S batteries and other catalysis applications.