One-step detonation-assisted synthesis of Fe3O4-Fe@BCNT composite towards high performance lithium-ion batteries
An Fe3O4-Fe@BCNT composite was successfully synthesized via detonation of a mixture of hexogen (C3H6N6O6) and ferrocene (C10H10Fe), in which bamboo-like carbon nanotubes encapsulating iron nanoparticles attached to Fe3O4 flakes (up to 58.1%) were formed. In the detonation process, hexogen was used to generate high temperature and high pressure, while ferrocene was used as a carbon source and catalyst. The recovered Fe3O4-Fe@BCNT composite was characterized by TEM, SEM, XRD, XPS, and Raman spectroscopy. The results indicate that multi-walled carbon tubes with a bamboo-like structure are formed, in which iron nanoparticles are encapsulated. The length of the multi-layered nanotubes (about 18–20 layers) is over 600 nm with diameters in the range of 20–30 nm. The content of Fe3O4 flakes dispersed into the carbon tubes is affected by the atomic ratio of C to Fe. In addition, the Fe3O4-Fe@BCNT composite exhibits excellent electrochemical performance as an anode material in Li-ion batteries. The charge–discharge coulombic efficiency is up to 81.1% in the first cycle. After 100 cycles, the discharge capacity steadily increases up to nearly 800 mA h g−1 due to activation. The rate capability of the Fe3O4-Fe@BCNT composite is also excellent at current densities ranging from 100 to 2000 mA g−1.
- This article is part of the themed collection: 2017 Nanoscale HOT Article Collection