Abstract
Carbon nanotubes (CNTs) filled with iron sulfide nanoparticles (NPs) are prepared by inserting sulfur and ferrocene into the hollow core of CNTs followed by heat treatment. It is found that pyrrhotite‐11T iron sulfide (Fe‐S) NPs with an average size of ≈15 nm are encapsulated in the tubular cavity of the CNTs (Fe‐S@CNTs), and each particle is a single crystal. When used as the anode material of lithium‐ion batteries, the Fe‐S@CNT material exhibits excellent electrochemical lithium storage performance in terms of high reversible capacity, good cyclic stability, and desirable rate capability. In situ transmission electron microscopy studies show that the CNTs not only play an essential role in accommodating the volume expansion of the Fe‐S NPs but also provide a fast transport path for Li ions. The results demonstrate that CNTs act as a unique nanocontainer and reactor that permit the loading and formation of electrochemically active materials with desirable electrochemical lithium storage performance. CNTs with their superior structural stability and Li‐ion transfer kinetics are responsible for the improved rate capability and cycling performance of Fe‐S NPs in CNTs.
Highlights
Carbon nanotubes (CNTs) filled with iron sulfide nanoparticles (NPs) are prepared by inserting sulfur and ferrocene into the hollow core of CNTs folstructure of rolled-up graphene layers, which creates a confined 1D cavity with diameters ranging from less than 1 nm lowed by heat treatment
We report the preparation of iron sulfide nanoparticle (NP)-filled CNTs by the synthesis reaction of sublimed sulfur with iron produced by the decomposition of ferrocene using CNTs as a nanoscale container and reactor and the electrochemical Li storage properties of the material when used as the anode
After further heat treatment in an inert atmosphere, iron sulfide NPs were formed inside the CNTs (Fe-S@CNTs, Figure 1d) by the reaction of sublimed sulfur with iron produced by the decomposition of ferrocene, using the CNTs as a nanoscale container and reactor
Summary
After further heat treatment in an inert atmosphere, iron sulfide NPs were formed inside the CNTs (Fe-S@CNTs, Figure 1d) by the reaction of sublimed sulfur with iron produced by the decomposition of ferrocene, using the CNTs as a nanoscale container and reactor. The appearance of sharp peaks indicates that the Fe-S NPs confined inside the CNTs are highly crystalline. Two voltage slopes are clearly seen at ≈1.8–2.0 V and ≈2.2–2.5 V
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
