Edge engineering of molybdenum disulfide coupling with heterostructure design enabling efficient adsorption and...

The employment of high-efficiency sulfur electrocatalysts to accelerate the sulfur redox reactions is extremely crucial for lithium‑sulfur (LiS) batteries. However, how to achieve the synergistic effects between strong chemical adsorption, fast ion diffusion and superior catalytic activity within one electrocatalyst still remains tremendous challenging. In this work, we conceptually demonstrate the delicate construction of the yolk-shell polyhedrons consisted of edge-rich molybdenum disulfide and iron sulfide heterostructure (denoted as ER-MoS₂/FeS) through a facile metal-organic framework-engaged strategy. Benefiting from the multiple advantages arising from the ER-MoS₂ edge sites and the heterointerfaces between ER-MoS₂ and FeS, the yolk-shell polyhedral ER-MoS₂/FeS heterostructure effectively enhances the chemical adsorption toward lithium polysulfides (LiPSs), accelerates the redox conversion kinetics, and facilitates the uniform deposition of Li₂S. In addition, the yolk-shell structure could provide more active sites and physically confine the polysulfide intermediates. Meanwhile, density functional theory (DFT) calculations confirm that the formation of ER-MoS₂/FeS heterostructure effectively enhances the electrical conductivity and chemical adsorption toward LiPSs. Consequently, the LiS batteries assembled with ER-MoS₂/FeS separators exhibit a remarkable discharge capacity of 1464.9 mAh g^-1 at 0.1C, as well as outstanding rate performance and long-term cycling stability. More importantly, both high‑sulfur-loading LiS batteries and LiS pouch cell are also fabricated and exhibit decent electrochemical performance, highlighting the significant potential for practical applications. This contribution provides a promising approach to engineer the structure and functionality of electrocatalysts in LiS chemistry.