Metal-organic framework derived FeS/MoS2 composite as a high performance anode for sodium-ion batteries

Considering the superior performances of MOF-based and MoS 2 -based materials, a flower-like FeS/MoS 2 composite is synthetized using MIL-100(Fe) as a precursor. Electronic density of states and band structure are simulated by density functional theory (DFT) calculations, which prove that FeS/MoS 2 heterostructure exhibits metallic behavior. Unique structure and powerful hetero-interface synergistic effect of FeS/MoS 2 is conducive to improve the stability of sodium-ion batteries (SIBs). It provides reversible capacities of 464 and 365 mA h g −1 at 0.1 and 1.0 A g −1 . When the current density increases to 5 A g −1 , FeS/MoS 2 delivers a high capacity of 325 mA h g −1 with a capacity retention rate (71.1%). Moreover, it can maintain a stable specific capacity of 331 mA h g −1 at 2.0 A g −1 after 200 cycles. Adsorption energy calculated by DFT indicates that more Na atoms may be trapped on the top of Mo atom between FeS and MoS 2 layers. This study may stimulate the interesting of multivariate-MOFs/ covalent organic frameworks (COFs) composite emerging two-dimensional materials and facilitate the application of composite electrode in high-performance SIBs.