Fundamentally Manipulating the Electronic Structure of Polar Bifunctional Catalysts for Lithium‐Sulfur Batteries: Heterojunction Design versus Doping Engineering

Abstract Heterogeneous structures and doping strategies have been intensively used to manipulate the catalytic conversion of polysulfides to enhance reaction kinetics and suppress the shuttle effect in lithium‐sulfur (Li‐S) batteries. However, understanding how to select suitable strategies for engineering the electronic structure of polar catalysts is lacking. Here, a comparative investigation between heterogeneous structures and doping strategies is conducted to assess their impact on the modulation of the electronic structures and their effectiveness in catalyzing the conversion of polysulfides. These findings reveal that Co 0.125 Zn 0.875 Se, with metal‐cation dopants, exhibits superior performance compared to CoSe 2 /ZnSe heterogeneous structures. The incorporation of low Co 2+ dopants induces the subtle lattice strain in Co 0.125 Zn 0.875 Se, resulting in the increased exposure of active sites. As a result, Co 0.125 Zn 0.875 Se demonstrates enhanced electron accumulation on surface Se sites, improved charge carrier mobility, and optimized both p ‐band and d ‐band centers. The Li‐S cells employing Co 0.125 Zn 0.875 Se catalyst demonstrate significantly improved capacity (1261.3 mAh g −1 at 0.5 C) and cycle stability (0.048% capacity delay rate within 1000 cycles at 2 C). This study provides valuable guidance for the modulation of the electronic structure of typical polar catalysts, serving as a design directive to tailor the catalytic activity of advanced Li‐S catalysts.