Hollow Structure Co1–xS/3D-Ti3C2Tx MXene Composite for Separator Modification of Lithium–Sulfur Batteries

The commercial application of lithium–sulfur (Li–S) batteries has faced obstacles, including challenges related to low sulfur utilization, structural degradation resulting from electrode volume expansion, and migration of polysulfide lithium (LiPSs). Herein, Co1–xS/3D-Ti3C2Tx composites with three-dimensional (3D) multilayered structures are used as separator modification materials for Li–S batteries to solve these problems. The multilevel layered structure of Co1–xS/3D-Ti3C2Tx establishes an efficient electron and Li+ transfer path, alleviates the volume change during the battery charge–discharge process, and enhances the stability of the structure. In addition, the battery assembled with the modified separator shows excellent discharge capacity and cycle stability at 0.5 C and could maintain a high discharge capacity after 500 cycles. This work provides a method for designing highly dispersed metal sulfide nanoparticles on MXenes and extends the application of MXenes-based composites in electrochemical energy storage.