Abstract: Lithium-sulfur (Li-S) batteries represent a promising energy storage system with the potential to replace traditional lithium-ion batteries. Recent research has explored the practical applications of Li-S batteries. However, due to the insulation properties of the sulfur components and the shuttle effect of polysulfides, the practical application of Li-S batteries is hindered by poor cycle stability and short life. In this study, we developed a controllable three-dimensional Ti₃C₂ structure design process, and through in situ growth of TiO₂ nanocrystals, we prepared three-dimensional porous materials with TiO₂@Ti₃C₂ heterostructures. These materials constructed using two-dimensional lamellar Ti₃C₂ function as a conductive skeleton to improve the conductivity of the sulfur cathodes, and through the in-situ growth of nano-TiO₂ to introduce more binding sites and provide more chemisorption sites to limit the dissolution and shuttle of polysulfides. In addition, the TiO₂@Ti₃C₂ heterointerface generated in situ on the surface of the lamellar structure can induce an internal electric field and increase active reaction sites, which promotes reaction kinetics, accelerates charge diffusion/transport, and promotes LiPS transformation. The materials designed in this study can effectively restrain the shuttle effect by realising the association process of adsorption, capture, and transformation of polysulfides. Thus, when applied as the sulfur cathode frame, it shows a high specific capacity of 1261.41 mAh g^-1 at a rate of 0.1 C. In addition, a specific capacity of 66.5 % is maintained over 500 cycles at a rate of 1 C. This strategy supports the development of Li-S batteries with extraordinary performance and opens up a promising way to design next-generation electrochemical energy storage devices.

Key words: Ti₃C₂, TiO₂, Multifunctional synergy, Heterogeneous interface, Lithium-sulfur battery