Hollow Structure Co 1- x S/3D-Ti 3 C 2 T x 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, Co 1- x S/3D-Ti 3 C 2 T x 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 Co 1- x S/3D-Ti 3 C 2 T x 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.