Enhancing Conversion Kinetics Through Electron Density Dual-Regulation of Catalysts and Sulfur Toward Room-/Subzero-Temperature Na-S Batteries

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 NaS. 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 at 0.1 A g and ultrahigh-rate capability (676.9 mAh g at 5.0 A g). Even at -10 °C, this cathode still delivers a high reversible capacity of 401.2 mAh g at 0.05 A g and 94% of the original capacitance after 50 cycles. This work provides a novel design idea for high-performance Na/S batteries.