3D hollow spheres comprising MXene/g-C3N4 heterostructre for efficient polysulfide adsorption and conversion in high-performance Li-S batteries

Suppressing the lithium polysulfides (LiPSs) shuttle and facilitating ion and charge transport in the electrode component resulting in effective sulfur conversion, is essential for the efficient functioning of lithium-sulfur (Li-S) batteries have substantial sulfur loading. In this study, a multifunctional cathode material based on a three-dimensional MXene and g-C3N4 hollow spheres framework was designed. This design aimed to create a conductive Platform with high absorptive and catalytic capability that would boost the performance of Li-S batteries in practical operating conditions. At the electrode level, the 3D hollow spherical architecture offers a large surface area to achieve high sulfur loading, preserves structure integrity in the electrode over significant volume changes of sulfur species, and facilitates diffusion of Li+ and electrolyte flow. At the molecular level, the pyridinic structure of g-C3N4 and the MXene conductive platform allows for fast sulfur conversion. The cathode, consisting sulfur ratio of 80%, exhibits a remarkable primary specific capacity of 1350.6 mAhg−1 at 0.1C. It retains 877.2 mAhg−1 after 100 cycles, showing a 65.2% retention rate. Furthermore, it exhibits exceptional electrochemical properties in terms of rate performance, giving a capacity of 632.5 mAhg−1 at a current of 4C. Our findings may have future technological consequences since they may speed the development of cost-effective and more efficient electrode materials for Li-S batteries.