Lithium–sulfur batteries are considered the next generation of energy storage devices, boasting high theoretical capacity, low cost, and environmental friendliness. However, the weak conductivity of sulfur and the shuttle effect of lithium polysulfides (LiPSs) are major challenges hindering lithium–sulfur battery development. Herein, a functional interlayer composite of Fe–Co sulfide/graphene/CNTs (FCS@GC) was prepared. The composite, which benefits from the 3D cross-linked network formed by CNTs and graphene, could avoid the agglomeration effect of the carbon material and enhance the physical adsorption capacity of LiPSs, effectively improving the transfer of Li⁺/e^–. Additionally, the loaded FeCoS₄ provides the composite with efficient chemical adsorption and conversion capacity of LiPSs, inhibits the shuttle effect at multiple levels, and greatly improves the kinetics. The lithium–sulfur battery, with FCS@GC as its functional interlayer, exhibits a stable specific capacity of 787.5 mA h g^–1 after 200 charge/discharge cycles at 0.5 C. Furthermore, it showcases an initial cycling capacity of 885.5 mA h g^–1 at 1 C. In addition, the capacity decay rate per cycle is only 0.036% after 800 cycles. After 110 cycles at a high sulfur loading of 5 mg cm^–2, lithium–sulfur batteries with an FCS@GC functional interlayer can still maintain a capacity of 750.5 mA h g^–1. The structure of this innovative compound will offer viable solutions for the issue of commercializing lithium–sulfur batteries.

中文翻译：

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三维网状铁钴硫化物/石墨烯/碳纳米管复合材料作为功能性夹层捕获和转化高性能锂硫电池的多硫化物

锂硫电池被认为是下一代储能装置，具有理论容量高、成本低、环境友好等优点。然而，硫的弱导电性和多硫化锂（LiPS）的穿梭效应是阻碍锂硫电池发展的主要挑战。在此，制备了Fe-Co硫化物/石墨烯/碳纳米管（FCS@GC）的功能性层间复合材料。该复合材料受益于CNT和石墨烯形成的3D交联网络，可以避免碳材料的团聚效应，增强LiPS的物理吸附能力，有效提高Li ⁺ /e ^–的传输。此外，负载的FeCoS ₄为复合材料提供了高效的LiPSs化学吸附和转化能力，在多个层面上抑制了穿梭效应，并大大提高了动力学性能。以FCS@GC作为功能中间层的锂硫电池，在0.5 C下经过200次充放电循环后，表现出稳定的比容量为787.5 mA hg ^{–1 。此外，其初始循环容量为885.5 mA hg –1}此外，在1 C下，800次循环后，每循环的容量衰减率仅为0.036%。在5 mg cm ^–2的高硫负载量下循环110次后，带有FCS@GC功能中间层的锂硫电池仍能保持750.5 mA hg ^–1的容量。这种创新化合物的结构将为锂硫电池商业化问题提供可行的解决方案。