Molecular Clip Strategy of Modified Sulfur Cathodes for High‐Performance Potassium Sulfur Batteries

Abstract Potassium‐sulfur (K‐S) batteries are severely limited by the sluggish reaction kinetics of the cyclooctasulfur (cyclo‐S₈) electrode with low conductivity, which urgently requires a novel cathode to facilitate activity to improve sulfur utilization. In this study, using the wet chemistry method, the molecular clip of Li⁺ is created to replace cyclo‐S₈ molecular with the highly active chain‐like S₆²⁻ molecular. The molecular clip strategy effectively lowers the reaction barrier in potassium‐sulfur systems, and the stretching of S─S bonds weakens the binding between sulfur atoms, facilitating the transformation of potassium polysulfides (KPSs). The as‐prepared cathode exhibits a reversible capacity of 894.8 mAh g⁻¹ at a current rate of 0.5 C. It maintains a long cycle life of 1000 cycles with a stable coulombic efficiency in the potassium–sulfur cells without cathode catalysts. Operando XRD and Raman spectra combined with density functional theory (DFT) calculations, revealing the high efficiency of enhanced conversion of potassium polysulfide for high‐performance K‐S batteries.