Electronic spin engineering: Catalytic mechanisms and development opportunities for polysulfide conversion in lithiumsulfur batteries

Electron spin serves as a pivotal quantum property that offers a revolutionary principle for overcoming kinetic limitations in lithium–sulfur (Li–S) batteries. As a fundamental quantum attribute, electron spin can be manipulated via spin state regulation, spin polarization, spin–orbit coupling, and crystal/ligand field effects to optimize orbital hybridization of active centers, adsorption strength of intermediates, and electron transfer pathways, thereby markedly boosting sulfur conversion kinetics. Recently, strategies encompassing intrinsic structural engineering, local coordination modulation, and external field coupling have been employed for precise spin state design, offering new opportunities to break the performance bottlenecks of Li–S batteries. This review systematically summarizes the theoretical fundamentals, regulation mechanisms, and structure–activity relationships of spin modulation in Li–S batteries, covering intrinsic structural engineering, local coordination tuning, and external field modulation, outlines the current research status and prevailing challenges, and provides future perspectives. It is anticipated to afford theoretical guidance for developing high-efficiency spin-based electrocatalysts and promoting the practical deployment of high-energy-density Li–S batteries.