3D Net-like GO-d-Ti₃C₂T_x MXene Aerogels with Catalysis/Adsorption Dual Effects for High-Performance Lithium–Sulfur Batteries

High theoretical specific capacity and rich resources in nature make sulfur an ideal cathode material for lithium–metal batteries. However, the shuttle effect and sluggish reduction reaction kinetics of lithium polysulfides (LiPSs) seriously affect the performance of the batteries. Here, we report GO-d-Ti3C2Tx MXene aerogels with a novel three-dimensional (3D) reticular structure that served as sulfur host cathode materials for lithium–sulfur batteries (LiSBs), which benefits adsorption/catalytic conversion of LiPSs simultaneously. The dissolved LiPSs can be rapidly captured through chemisorption and then catalyzed into insoluble Li2S by low-coordinated-state Ti on the d-Ti3C2Tx MXene surface. The combination of adsorption and catalysis enormously improves the capacity and cycling performance of LiSBs. At an S mass loading of 1.5 mg cm–2, the cell with the S@GM0.4 composite electrode achieves excellent cycling performance. The discharge specific capacity of 1039 mA h g–1 (1.56 mA h cm–2) decays to 542.9 mA h g–1 after 1000 cycles with a capacity fading rate of 0.048% per cycle at 0.5 C. Even at an S mass loading of 4.88 mg cm–2, an areal capacity of 4.3 mA h cm–2 can be achieved at 0.2 C.