Engineering TiO2/ZnS@MXene three-phase heterostructure for enhanced polysulfide capture and sulfur kinetics in high-performance lithium-sulfur batteries

The practical application of high-performance lithium‑sulfur batteries (LSB) was primarily hindered by polysulfides shuttling and sluggish sulfur redox kinetics. To overcome these limitations, this study introduces a multifunctional three-phase heterostructured TiO 2 /ZnS@MXene catalyst engineered to synergistically combine high adsorption capacity and strong catalytic activity. The TiO 2 component, known for its' strong chemical affinity and ZnS, serving as an efficient electrocatalyst, were homogeneously anchored onto the highly conductive MXene substrate via in situ growth. Additionally, the MXene hollow microsphere structure effectively inhibited the self-stacking of lamellar host to ensure the maximum exposure of the active sites, providing a favorable buffer space for the volume expansion throughout the reaction process. The elaborately integrated TiO 2 /ZnS@MXene heterostructure provides a synergistic effect to realize the function of sequential capture-diffusion-transformation of sulfur species throughout the reaction process. As a result, the LSB containing TiO 2 /ZnS@MXene heterostructures could retain 821.7 mAh g −1 after 1000 cycles at 1C with only 0.010 % capacity decay per cycle. Even with a sulfur content of 5.8 mg cm −2 and lean electrolyte conditions (5.1 μL mg −1 ), it still delivers an area capacity of 4.1 mAh cm −2 at 0.2C.