In Situ Built Nanoconfined TiO2 Particles in Robust‐Flexible MXene@rGO Conductive Framework Enabling High‐Performance Hybrid Magnesium–Sulfur Batteries

Abstract The exploration of new and efficient sulfur cathodes through nanostructured materials design is vital for the development of high‐performance metal–sulfur batteries, which is a promising candidate for next‐generation energy storage systems. However, the shuttle behavior and sluggish reaction kinetics of polysulfides hinder the application of sulfur cathodes. Herein, a 3D MXene/reduced graphene oxide (rGO) composite conductive framework with superior specific surface area, structural stability, and ionic/electronic conductivity is constructed. On this basis, the TiO 2 nanoparticles, in situ grown in the interlayer between MXene and rGO can be used as adsorptive and catalytic active site for polysulfides to accelerate the electrochemical reaction kinetics and alleviate the shuttle effect, thereby improving cycle stability. Consequently, the sulfur‐loaded MXene‐TiO 2 @rGO composite electrodes present a high reversible capacity of 1052.0 mAh g −1 at 0.2 C after 200 cycles, favorable high‐rate capability, and splendid long‐term performance, retaining 445.6 mAh g −1 capacity after 1000 cycles at 2 C in hybrid Mg/Li–S batteries. This work provides a new insight for using MXene as the sulfur host with high performance for metal–sulfur batteries.