Rationally designed NiS₂-MnS/MoS₂ hybridized 3D hollow N-Gr microsphere framework-modified celgard separator for highly efficient Li-S batteries

This work develops a multifunctional separator, as trapper-catalyst-conductor, for Li-S batteries through modifying a Celgard separator by a novel hybrid comprising NiS₂-MnS on a MoS₂ nanosheets/3D hollow N-doped graphene microsphere framework. Benefiting from the great adsorption ability of MoS₂ and NiS₂-MnS for polysulfide species, the separator demonstrates high-efficiency polysulfide trapping. The ultrafine NiS₂-MnS nanoparticles induce the developed separator to offer abundant catalytic active sites and efficient catalytic behavior for fast polysulfide redox. Furthermore, the super-structured N-doped 3D hollow graphene microsphere substrate can prevent both NiS₂-MnS and MoS₂ from agglomeration phenomenon during the synthesis/operation process, while providing a highway for electron transportation to catalytic active sites. Importantly, the excellent mesoporous architecture of the coating material facilitates the diffusion of Li ion. Therefore, the Li-S battery constructed by the proposed separator shows a much higher performance and superior cycling stability than that of the cell using pristine Celgard separator.