ENHANCED POLYSULFIDE REGULATION IN RECHARGEABLE LI-S BATTERIES WITH ZnS AS ELECTROCATALYST: EXPERIMENTAL VALIDATION AND INTERFACIAL INSIGHTS FROM SIMULATIONS.

Abstract

We present a high-performance lithium-sulfur (Li-S) battery cathode based on a reduced graphene oxide (rGO)-decorated ZnS nanosphere structure, which serves as a multifunctional sulfur host. The rGO framework provides a high-surface-area conductive network for enhanced sulfur loading, while ZnS acts as an electrocatalyst to accelerate polysulfide conversion. Fabricated via a one-step hydrothermal method, the composite achieves a high sulfur content (~80%) with efficient polysulfide confinement and catalytic conversion as a Li-S battery cathode. As a result, it delivers an initial capacity of 1014 mAh/g at 0.1 C and retains 592 mAh/g at 1C, demonstrating excellent rate capability and cycling stability (479 mAh/g over 200 cycles at 1C). To further understand the interfacial interactions, molecular dynamics simulations were conducted, revealing the role of ZnS in accelerating lithium polysulfide (LiPS) conversion, particularly from Li₂S₄ to Li₂S. The study analyzed LiPS diffusion coefficients and potential energy across different sulfur species, confirming the superior efficiency of the rGO@ZnS host. These findings highlight the potential of ZnS-decorated rGO structures as a promising approach to improving Li-S battery performance through enhanced sulfur utilization and polysulfide regulation.