Enhanced Electron Delocalization within Coherent Nano‐Heterocrystal Ensembles for Optimizing Polysulfide Conversion in High‐Energy‐Density Li‐S Batteries

Abstract Commercialization of high energy density Lithium‐Sulfur (Li‐S) batteries is impeded by challenges such as polysulfide shuttling, sluggish reaction kinetics, and limited Li⁺ transport. Herein, a jigsaw‐inspired catalyst design strategy that involves in situ assembly of coherent nano‐heterocrystal ensembles (CNEs) to stabilize high‐activity crystal facets, enhance electron delocalization, and reduce associated energy barriers is proposed. On the catalyst surface, the stabilized high‐activity facets induce polysulfide aggregation. Simultaneously, the surrounded surface facets with enhanced activity promote Li₂S deposition and Li⁺ diffusion, synergistically facilitating continuous and efficient sulfur redox. Experimental and DFT computations results reveal that the dual‐component hetero‐facet design alters the coordination of Nb atoms, enabling the redistribution of 3D orbital electrons at the Nb center and promoting d‐p hybridization with sulfur. The CNE, based on energy level gradient and lattice matching, endows maximum electron transfer to catalysts and establishes smooth pathways for ion diffusion. Encouragingly, the NbN‐NbC‐based pouch battery delivers a Weight energy density of 357 Wh kg⁻¹, thereby demonstrating the practical application value of CNEs. This work unveils a novel paradigm for designing high‐performance catalysts, which has the potential to shape future research on electrocatalysts for energy storage applications.