Multiwalled Carbon Nanotubes/Co3O4 Nanocomposites and Its Electrochemical Performance in Lithium Storage

Multiwalled carbon nanotubes (MWNTs) coated with a thick layer of Co3O4 nanocrystals were prepared through a facile and effective method for the first time, which combined the acid treatment MWNTs and in situ decomposition of Co(NO3)2 in nhexanol solution at 140 °C. TEM images show that the MWNTs are nearly fully coated with a layer of Co3O4 with an average size of 8 nm. The coating layer is 15–20 nm in thickness. The electrochemical performance in Li+ insertion and extraction reactions shows that the MWNTs/Co3O4 composites have larger lithium storage capacities and a better cycle-ability.