Amorphous carbon coated multiwalled carbon nanotubes@transition metal sulfides composites as high performance anode materials for lithium ion batteries

Transition metal sulfides as anodes for lithium-ion batteries (LIBs) have attracted much attention because of their large Li+ storage capacity. However, the lower electrical conductivity and rapid capacity fading during the charge/discharge process strictly prohibit their practical applications. Here, a new strategy is adopted to accommodate the volume change and enhance the electrical conductivity by anchoring Co1-xS and NiS nanocrystals on amorphous carbon coated multiwalled carbon nanotubes (CNTs). Benefiting from the unique structure, the Co1-xS and NiS anodes present excellent electrochemical performances including remarkable cyclability and outstanding rate property. Furthermore, the electrochemical reaction process of the anodes is investigated by high-resolution transmission electron microscope and X-ray photoelectron spectroscopy technique.