Engineering Spin State of Metal Sites toward Advanced Lithium-Sulfur Batteries

Abstract

Developing efficient catalysts is essential for mitigating the shuttle effect and accelerating the conversion kinetics of polysulfides in lithium-sulfur (Li-S) batteries. To date, numerous strategies have been employed to optimize the performance of catalysts. Among these strategies, regulating the spin state of metal sites can modulate the d orbital occupancy and enable precise control over catalyst-polysulfide interactions, which provides an effective approach for the catalysts to optimize the balance between adsorption and catalysis toward polysulfide conversion. This review offers a comprehensive overview of spin-state engineering of the catalysts for Li-S batteries for the first time, detailing the strategies for spin-state modulation and the relevant characterization techniques for monitoring these changes. Finally, we underscore the critical role of spin-state tuning in optimizing catalytic active centers and propose future research directions in this emerging field.