Hierarchical NiCoO2 nanosheets supported on amorphous carbon nanotubes for high-capacity lithium-ion batteries with a long cycle life

In this paper, we report a facile approach to the synthesis of one-dimension (1D) hierarchical NiCoO2 nanosheets (NSs)@amorphous CNT composites based on the templates and carbon source of polymeric nanotubes (PNTs). Importantly, these sulfonated PNTs can also be used to prepare many other functional 1D metal oxides@amorphous CNT nanostructures, such as TiO2, SnO2, CoO and NiO, etc. Due to the outstanding nanostructures and the synergistic effects of the NiCoO2 NSs and amorphous CNTs, an ultrahigh discharge capacity of 1309 mA h g−1 is delivered by the NiCoO2@CNT composites, even after 300 cycles at a current density of 400 mA g−1. The favorable improvements of the NiCoO2 based lithium-ion batteries (LIBs) reported in this work illustrate that the 1D amorphous carbon matrix offers significant benefits for high-capacity metal oxide anode nanomaterials.