Boosting Li-S Battery Performance via Metal-Organic Framework-Modified Separator and Graphitized Hollow Carbon Sphere...

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.