Boosting Li–S Battery Performance via Metal-Organic Framework-Modified Separator and Graphitized Hollow Carbon Sphere Sulfur Cathode for Effective Polysulfide Shuttle Suppression

The sluggish kinetics of multiphase reactions and severe lithium polysulfide (LiPS) shuttling hinder the practical application of lithium-sulfur (Li-S) batteries, despite their promise for future energy storage. To tackle these challenges, we propose a vertically aligned Co₉S₈ nanoarray derived from a metal-organic framework (MOF), featuring excellent conductivity and grown directly on a Celgard separator. It integrates indium(III) phthalocyanines (InPc) (MOF Co₉S₈@InPc-Celgard) using a solution reaction technique, thereby forming a strong barrier against LiPSs in Li-S batteries. By employing the direct growth of vertical MOF Co₉S₈@InPc arrays as a versatile polar barrier, the MOF Co₉S₈@InPc-Celgard separator features an extensive surface area, excellent mechanical stability, and superior efficiency in sequestering LiPSs via chemical and physical interactions. Similarly, this study also introduces a cathode material based on mesoporous hollow carbon, featuring an in situ-grown nitrogen-doped graphitic carbon nanoshell (NGCNs) matrix with embedded cobalt nanoparticles as an efficient sulfur host. Using MOF chemistry, a surfactant-free synthesis produces a carbon structure with multiple porosities, including a hollow core and mesoporous shell. Due to its advantageous properties, the Co@NGCNs/S composite electrode enables high sulfur loading, and the incorporation of the MOF-derived Co₉S₈@InPc-Celgard separator into Li-S cells results in excellent electrochemical performance. Thus, the Li-S battery with a MOF Co₉S₈@InPc-Celgard/Co@NGCNs/S achieved a discharge-specific capacity of 1325 mAh g^{- 1} at a 0.1 C rate. Additionally, the developed Li-S pouch cell possesses robust cycling performance, emphasizing its promise for practical applications.