Preparation of Fe3O4/FexSy heterostructures via electrochemical deposition method and their enhanced electrochemical performance for lithium-sulfur batteries

Lithium-sulfur (Li–S) batteries have received more and more attention due to their excellent theoretical capacity. However, Li–S battery shuttle effect, poor conductivity, slow chemical reaction kinetics and other shortcomings inhibit its development. In this paper, Fe3O4/FexSy heterostructures were prepared by electrochemical deposition method followed by thermal annealing. The samples obtained at 600 °C have high crystallinity and novel morphology, which is conducive to the adsorption and catalytic performance of LiPSs. As cathode host, folded tubular heterostructures can contribute to sulfur loading and improve Li-ion diffusion rate, thus improving sulfur utilization and cycling stability. Combined with these merits, the Li-S batteries showed excellent stability over 500 cycles at 0.5 C, with an average capacity decay of 0.067% per cycle. This work provides an effective method for rapidly preparing multifunctional heterostructures for Li–S batteries.