Self-assembled 3D NiCo2S4 nanotubes-graphene aerogel composites as an excellent anode for Li-ion batteries

Three-dimensional nickel cobalt sulphide (NiCo2S4) nanotubes-graphene aerogel composites (NGAs) are firstly assembled by an electrostatic interaction between the diallyldimethylammonium chloride-modified NiCo2S4 nanotubes and graphene oxide (GO) sheets, followed by a steerable hydrothermal and freeze-drying process. The final samples are characterised by scanning electron microscope, transmission electron microscopy, X-ray diffraction and Brunauer-Emmett-Teller. The results reveal that the NiCo2S4 nanotubes with a uniform diameter of about 200 nm tightly anchor onto the crumpled surface of graphene sheets and GO sheets self-assemble into an interconnected porous structure. When the composites are evaluated as an anode for lithium-ion batteries (LIBs), presenting an extremely admirable cycling stability (967.5 mAh g(-1) after 100 cycles at a current density of 100 mA g(-1)) and excellent rate capability (as high as 654.7 mAh g(-1) at a large rate of at 2000 mA g(-1)). This work proved that the NGAs may have a great application in LIBs.