Synthesis of NiO/carbon shell/single-walled carbon nanotube composites as anode materials for lithium ion batteries

In this study, NiO/carbon shell/single-walled carbon nanotube composites are prepared by heat treating the single-walled carbon nanotube samples synthesized by direct current arc discharge method. The morphology and nanostructure of the composites are affected by the heat treatment temperature according to the X-ray diffraction, Raman spectra and high-resolution transmission electron microscopy results. The electrochemical measurements are evaluated in coin-type cells versus metallic lithium. After heat treatment in H-2 at 600 degrees C for 1 h and in air at 300 degrees C for 10 h, the NiO nanoparticles encapsulated by carbon shells are evenly distributed on the surface of web-like single-walled carbon nanotubes and a perfect NiO/carbon shell/single-walled carbon nanotube nanostructure is formed. This NiO/carbon shell/single-walled carbon nanotube composite shows a high reversible specific capacity of 758 mA h g(-1) after 60 cycles at a current density of 100 mA g(-1) and an excellent rate capacity of about 594 mA h g(-1) even at a high current density of 1600 mA g(-1). Therefore, the NiO/carbon shell/single-walled carbon nanotube composites have significant potential for applications in energy storage devices. (C) 2015 Elsevier Masson SAS. All rights reserved.