Orbital engineering for polysulfide redox catalysis: from fundamental descriptors to rational design of high-performance Li–S batteries

The practical application of lithium–sulfur (Li–S) batteries is severely hindered by the shuttle effect of soluble lithium polysulfides (LiPSs) and their sluggish conversion kinetics. To address these challenges, the rational design of advanced electrocatalysts is widely regarded as a pivotal solution. Fundamentally, the catalytic efficacy of electrocatalysts is intrinsically governed by their electronic structures and local coordination environments, which subsequently dictate the adsorption energies, charge transfer kinetics, and selectivity of reaction pathways. However, existing reviews predominantly remain confined to phenomenological summaries of material syntheses and electrochemical performances, largely failing to elucidate how macroscopic physical modulation strategies alter the aforementioned electronic properties by driving “intrinsic orbital reconstruction.” To bridge this gap, this review comprehensively dissects the cutting-edge physical modulation strategies, including defect engineering, heteroatom doping, heterointerface construction, lattice strain engineering, and multi-component synergistic orbital design. We provide in-depth insights into how these strategies precisely reconstruct the coordination configurations and intrinsic orbitals of active centers at the atomic scale, thereby fundamentally overcoming the kinetic bottlenecks associated with LiPS conversion. Finally, we outline the primary challenges currently faced in modulating electronic structures and present forward-looking perspectives on future development directions, aiming to provide advanced insights into intrinsic electronic structure modulation within Li–S chemistry.