Rational-designed integrated cathode of bimetallic sulfides/ electrospun carbon nanofibers with hierarchical structure toward electrochemical energy storage.

[Display omitted] • The bimetallic sulfides and electrospun carbon nanofibers are integrated. • The high conductivity and active sites promote adsorption and catalytic conversion. • The cathode with hierarchical structure shows excellent electrochemical performance. As a new generation of energy storage systems, lithium-sulfur batteries (LSBs) with high energy density up to 2600 Wh kg−1 present broad development prospects. However, their practical applications are faced with the problems of slow redox kinetics as well as shuttle effect of lithium polysulfides (LiPSs). Herein, we have developed a structure and function integrated cathode of bimetallic sulfides/electrospun carbon nanofibers. The rational designed cathode with hierarchical structure can achieve the physical confinement of polysulfide and accommodate sulfur volume expansion/contraction throughout the lithiation/delithiation cycle to alleviate the impact of volume expansion during conversion process of sulfur. And bimetallic sulfides with high electron conductivity and abundant chemical active sites not only can provide fast transmission paths for electrons and ions but also anchor LiPSs through Lewis acid-base interactions suppressing shuttle effect efficiently, finally reducing polarization and overpotential. Therefore, the well-designed sulfur-host cathode shows remarkable reversible capacity of 908.6 mAh g−1 at 2C and still has specific capacity of 680.1 mAh g−1 after 500 cycles at 1C, further demonstrating practicality feasibility of this design. [ABSTRACT FROM AUTHOR]