A three-dimensional crosslinked nano-structure via in situ growth of carbon nanotube/cobalt sulfide composites on porous carbon nanofibers for enhanced sodium storage.

A three-dimensional crosslinked CFs@CNT/CoSx nanocomposite was successfully synthesized by in situ growing carbon nanotubes on carbon nanofibers and a facile sulfurization process. The carbon nanotubes synthesized by sintering melamine under the catalysis of cobalt can increase the specific surface areas and provide abundant sodium ion diffusion channels for the composite. Meanwhile, the formed cobalt sulfide nanoparticles will increase the active sites on the surface of CFs@CNT/CoSx. Due to the rational design of the composite structure, such an anode can deliver a specific capacity of 423.7 mA h g-1 after 100 cycles at 100 mA g-1 and exhibit superior rate performance of retaining 324.1 mA h g-1 at 2 A g-1 for sodium storage.