Hollow\nStructure Co_1–<i>x</i>S/3D-Ti₃C₂T_<i>x</i> MXene Composite for Separator\nModification of Lithium–Sulfur\nBatteries

Abstract

The\ncommercial application of lithium–sulfur (Li–S)\nbatteries has faced obstacles, including challenges related to low\nsulfur utilization, structural degradation resulting from electrode\nvolume expansion, and migration of polysulfide lithium (LiPSs). Herein,\nCo_1–<i>x</i>S/3D-Ti₃C₂T_<i>x</i> composites with three-dimensional\n(3D) multilayered structures are used as separator modification materials\nfor Li–S batteries to solve these problems. The multilevel\nlayered structure of Co_1–<i>x</i>S/3D-Ti₃C₂T_<i>x</i> establishes an\nefficient electron and Li⁺ transfer path, alleviates the\nvolume change during the battery charge–discharge process,\nand enhances the stability of the structure. In addition, the battery\nassembled with the modified separator shows excellent discharge capacity\nand cycle stability at 0.5 C and could maintain a high discharge capacity\nafter 500 cycles. This work provides a method for designing highly\ndispersed metal sulfide nanoparticles on MXenes and extends the application\nof MXenes-based composites in electrochemical energy storage.