Abstract
Room-temperature sodium-sulfur (RT Na/S) batteries have received increasing attention for the next generation of large-scale energy storage, yet they are hindered by the severe dissolution of polysulfides, sluggish redox kinetic, and incomplete conversion of sodium polysulfides (NaPSs). Herein, the study proposes a dual-modulating strategy of the electronic structure of electrocatalyst and sulfur to accelerate the conversion of NaPSs. The selenium-modulated ZnS nanocrystals with electron rearrangement in hierarchical structured spherical carbon (Se-ZnS/HSC) facilitate Na(+) transport and catalyze the conversion between short-chain sulfur and Na(2)S. And the in situ introduced Se within S can enhance conductivity and form an S─Se bond, suppressing the "polysulfides shuttle". Accordingly, the S@Se-ZnS/HSC cathode exhibits a specific capacity of as high as 1302.5 mAh g(-1) at 0.1 A g(-1) and ultrahigh-rate capability (676.9 mAh g(-1) at 5.0 A g(-1)). Even at -10 °C, this cathode still delivers a high reversible capacity of 401.2 mAh g(-1) at 0.05 A g(-1) and 94% of the original capacitance after 50 cycles. This work provides a novel design idea for high-performance Na/S batteries.