The metal–organic framework mediated synthesis of bell string-like hollow ZnS–C nanofibers to enhance sodium storage performance

Zinc sulfide (ZnS), with a high theoretical capacity and low redox potential, is considered to be a promising anode material for use in sodium-ion batteries (SIBs). However, the dissolution of polysulfides and the structural collapse of ZnS will undoubtedly lead to inferior electrochemical properties. Herein, a bell string-like hollow ZnS-C nanofibers (ZnS@CNFs) film, which displays the unique structural integration of metal–organic framework (MOF)-derived hollow ZnS and three-dimensional (3D) N, S co-doped carbon nanofiber networks, is successfully fabricated via MOF-mediated electrospinning followed by solvothermal sulfuration and pyrolysis processes. The as-prepared ZnS@CNFs films, as free-standing anodes for SIBs, exhibit an excellent adsorption capacity for polysulfides and outstanding sodium storage performance owing to the existence of C–S bonds and conductive pathways. As a result, the ZnS@CNFs anodes show superior rate capabilities (258.3 mA h g−1 at 10 A g−1 with a high initial coulombic efficiency (ICE) of 88.4%) and cycling stability (decay ratio of 0.029% per cycle after 500 cycles at 1 A g−1). Finally, ZnS@CNFs//Na3V2(PO4)3 full-cells achieve a high energy density of 156.9 W h kg−1. This work sheds light on the potential application of MOF-derived ZnS anodes for use in high-performance SIBs.