Polyvinyl Chloride‐Derived Organosulfur Cathodes for Durable Li–S Battery

The properties of sulfur host materials are critical for mitigating the lithium polysulfide (LiPS) shuttle effect and prolonging the Li–S battery lifetime. Herein, we have developed a unique polyvinyl chloride (PVC)‐derived polymeric host material (named as XC); results show that XC host is capable of achieving strong chemical/physical confinement to the encapsulated sulfur and lithium polysulfide (LiPS) intermediates, thus significantly reducing the shuttling effect and improving the battery cycle life to above 500 cycles with only 9.3% capacity loss (74.4% after 1000 cycles). While with increased S loading of 6.2 mg‐S/cm 2 and electrolyte‐to‐sulfur ratio of 6 μL/mg‐S, the XC/S28 composite comprising 20% XC and 80% S maintains 67.5% of its capacity at the 200 th cycle. Apart from the chemical immobilization of short‐chain S x ( x = 2−4) in micropores or organic skeletons, the use of XC as a polymeric encapsulant still maintains the solid–liquid–solid conversion in highly solvating electrolytes, guaranteeing high discharge voltage and energy while significantly extending cycle life.