Heterocycle‐Bridged Short Sulfur‐Chain Polymers for Polysulfide‐Suppressing Cathodes in Lithium‐Organosulfide Batteries

ABSTRACT Organosulfur polymers, valued for their structural tunability and environmental friendliness as cathode materials for lithium‐sulfur (Li‐S) batteries, face challenges in practical applications due to inadequate cycling stability and rate performance. Herein, we report the rational design and green synthesis of a heterocycle‐bridged short sulfur‐chain polymer, namely poly(pyrazine tetrasulfide) (PPZTS), with a sulfur‐rich atomic chain structure as a high‐performance cathode material for lithium‐organosulfide batteries. The pyrazine‐bridged short sulfur‐chain structure in PPZTS prevents the formation and shuttling of long‐chain polysulfides, and the electronegative π‐conjugated pyrazine rings facilitate uniform Li + diffusion, leading to significant improvements in both cycling stability and rate performance. The PPZTS cathode achieves a high capacity of 1250 mAh g −1 at 0.1 A g −1 and 660 mAh g −1 at 5.0 A g −1 . When cycled at 1.0 A g −1 , the PPZTS cathode demonstrates an initial capacity of 850.9 mAh g −1 and retaining 630.4 mAh g −1 after 400 cycles. The PPZTS cathode also demonstrates robust performance across a wide temperature range from −20 to 80°C, and the deployment in soft‐packed batteries further suggests its potential practicability. This work underscores the intriguing potential of heterocycle‐linked short sulfur‐chain polymers as cathode materials for alkali metal‐organosulfide batteries, addressing key challenges in organosulfur polymer applications for advanced energy storage devices.