Amorphous bismuth tin oxide nanosheet catalysts for high-performance room-temperature sodium-sulfur batteries.

Room-temperature sodium-sulfur (RT Na-S) batteries are hindered by polysulfide shuttling, sluggish redox kinetics, limited reversible capacity, and rapid capacity decay, which collectively impede their practical deployment. Incorporating electrocatalysts with a high density of active sites offers a promising route for accelerating reaction kinetics. In this study, we rationally designed ultrathin amorphous bismuth tin oxide nanosheet catalysts. In situ Raman spectroscopy and electrochemical analysis reveal that the amorphous structure optimizes adsorption-desorption equilibria and accelerates redox kinetics, effectively suppressing polysulfide shuttling and overcoming the inherently slow reaction kinetics. Consequently, the a-BiSnOx/S electrode delivers a high reversible capacity of 1334.7 mAh g-1 at 0.2C after 300 cycles and exhibits outstanding long-term cycling stability, retaining 819.2 mAh g-1 at 3C after 3000 cycles. The findings and insights presented in this study provide an important reference for the development of high-performance electrocatalysts for room-temperature Na-S batteries.