Ordered structure of interlayer constructed with metal-organic frameworks improves the performance of lithium-sulfur batteries

Lithium-sulfur (Li-S) battery has attracted intensive attention in the realm of energy storage owing to its high theoretical capacity and energy density. However, the shuttle effect of soluble lithium polysulfides (LiPSs) between electrodes results in rapid capacity degradation. Herein, a strategy which combines the design of both chemical interaction and microstructure of interlayer was proposed to suppress the shuttle effect. The chemical interaction between different functionalized MOFs and LiPSs was systematically studied to find the best candidate. Furthermore, an interlayer with ordered structure was constructed via the layer-by-layer assembly of metal-organic frameworks (MOFs) on graphene (UiO-66-NH₂@graphene) to create sinuous channels which can better impede the diffusion process of LiPSs by the strong adsorption of MOF toward LiPSs. Consequently, in comparison to the battery with a bare separator, the ordered interlayer increased the initial discharge capacity of battery by 28.98% at 1.0 C and lowered the capacity decay rate remarkably from 0.10% to 0.067% per cycle, indicating that the design of chemical interaction and microstructure paves the way for high-performance Li-S batteries.