Design Strategies of S8 Molecule Cathodes for Room-Temperature Na-S Batteries

Sodium-sulfur batteries have been provided as a highly attractive solution for large-scale energy storage, benefiting from their substantial storage capacity, the abundance of raw materials, and cost-effectiveness. Nevertheless, conventional sodium-sulfur batteries have been the subject of critique due to their high operating temperature and costly maintenance. In contrast, room-temperature sodium-sulfur batteries exhibit significant advantages in these regards. The most commonly utilized cathode active material is the S8 molecule, whose intricate transformation process plays a crucial role in enhancing battery capacity. However, this process concomitantly generates a substantial quantity of polysulfide intermediates, leading to diminished kinetics and reduced cathode utilization efficiency. The pivotal strategy is the design of catalysts with adsorption and catalytic functionalities, which can be applied to the cathode. Herein, we present a summary of the current research progress in terms of nanostructure engineering, catalyst strategies, and regulating sulfur species conversion pathways from the perspective of high-performance host design strategy. A comprehensive analysis of the catalytic performance is provided from four perspectives: metal catalysts, compound catalysts, atomically dispersed catalysts, and heterojunctions. Finally, we analyze the bottlenecks and challenges, offering some thoughts and suggestions for overcoming these issues.