Preparation and electrochemical properties of electrospun FeS/carbon nanofiber composites

Carbon nanocomposites are widely used in hydrogen storage materials and high-capacity electrode materials due to their unique structures and excellent performances. In this study, an FeS-CNF composite material is prepared with FeS nanoparticles either embedded in or attached to carbon fibers by electrospinning. The FeS nanoparticles are uniformly and tightly anchored on the surface of the carbon nanofibers. The structure and morphology of FeS-CNFs are characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). As an alkaline battery anode, the FeS-CNF composite material has superior charging and discharging capacity and excellent cycling stability without any conductive additives. At the current density of 2 A g −1 , the specific capacitance of FeS-CNFs reaches 503 F g −1 ; over 80% of initial capacitance is retained as the current density improves from 2 to 10 A g −1 and it also exhibits an excellent cycling performance with 90% capacitance retention after 1000 times charge/discharge cycles. The excellent electrochemical performance is attributed to the synergistic effect between FeS and carbon nanofibers, which shortens ion diffusion paths and effectively prevents sulfide volume expansion.