Rational Designing MxSy@C (M＝Ni, Co, Zn, Cu, Mn) Composites With Controlled Polysuifides Shuttling Behaviors Towards Advanced Stable Room Temperature Na－S Batteries

Room-temperature sodium-sulfur (RT-Na/S) batteries display attractive potential in large-scale energy-storage, but their practical application was still restricted by the serious dissolution of polysulfides. Herein, supported by the constructing of interface engineering, the metal sulfide-carbon nanocomposite can be prepared with considerable electrochemical properties. Utilizing the double-helix structure of carrageenan-metal hydrogels as precursors, in-situ metal sulfide (MxSy) nanostructure/3D carbon aerogels (3D CAs) can be successfully constructed. Importantly, with the assistance of the vulcanization process, 3D carbon architecture was maintained in the composites and act as a skeleton to optimize their structural stability. As the anode of RT-Na/S batteries, ZnS/S@C and NiS2/S@C delivered an excellent cycling stability and rate performance (179.8mAhg−1 at 20Ag−1 after 10000 cycling for ZnS/S@C, 220.3 mAhg−1 at 10Ag−1 after 3000 cycling for NiS2/S@C). The detailed investigation of mechanism revealed that the powerful adsorption for Na2S4 was originated from 3D metal sulfide-carbon structure. The well-designed architecture of sulfide-carbon composites servers as an electrocatalyst to alleviate the shuttle effect of polysulfides, resulting in the long-term electrochemical stability. Given this, the work is expected to provide promising insights for designing advanced anode materials for RT-Na/S batteries.