Nanoconfining ultrafine heterostructured sulfides in carbon nanofibers enabling ultrastable and fast sodium storage

A nanoconfinement strategy coupled with electrospinning technique is proposed to incorporate the ultrafine Co9S8/WS2@C particles in one-dimensional carbon nanofibers. Benefitting from the ultrasmall nanoparticles, the heterostructures of Co9S8/WS2, and the construction of conductive and protective carbon skeleton, the obtained Co9S8/WS2@C@CNF delivers a comprehensive Na-ions storage ability.