Lithium–sulfur (Li–S) batteries demonstrate great potential for next-generation electrochemical energy storage systems because of their high specific energy and low-cost materials. However, the shuttling behavior and slow kinetics of intermediate polysulfide (PS) conversion pose a major obstacle to the practical application of Li–S batteries. Herein, CrP within a porous nanopolyhedron architecture derived from a metal–organic framework (CrP@MOF) is developed as a highly efficient nanocatalyst and S host to address these issues. Theoretical and experimental analyses demonstrate that CrP@MOF has a remarkable binding strength to trap soluble PS species. In addition, CrP@MOF shows abundant active sites to catalyze the PS conversion, accelerate Li-ion diffusion, and induce the precipitation/decomposition of Li2S. As a result, the CrP@MOF-containing Li–S batteries demonstrate over 67% capacity retention over 1000 cycles at 1 C, ∼100% Coulombic efficiency, and high rate capability (674.6 mAh g–1 at 4 C). In brief, CrP nanocatalysts accelerate the PS conversion and improve the overall performance of Li–S batteries.

Despite their high specific energy and great promise for next-generation energy storage, lithium–sulfur (Li–S) batteries suffer from polysulfide shuttling, slow redox kinetics, and poor cyclability. Catalysts are needed to accelerate polysulfide conversion and suppress the shuttling effect. However, a lack of structure–activity relationships hinders the rational development of efficient catalysts. Herein, we studied the Nb–V–S system and proposed a V-intercalated NbS2 (Nb3VS6) catalyst for high-efficiency Li–S batteries. Structural analysis and modeling revealed that undercoordinated sulfur anions of [VS6] octahedra on the surface of Nb3VS6 may break the catalytic inertness of the basal planes, which are usually the primary exposed surfaces of many 2D layered disulfides. Using Nb3VS6 as the catalyst, the resultant Li–S batteries delivered high capacities of 1541 mAh g–1 at 0.1 C and 1037 mAh g–1 at 2 C and could retain 73.2% of the initial capacity after 1000 cycles. Such an intercalation-induced high activity offers an alternative approach to building better Li–S catalysts.

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