Carbon Nanotubes-Doped Metal Oxides and Metal Sulfides Heterostructure Achieves 3D Morphology Deposition of Li₂S and Stable Long-Cycle Lithium–Sulfur Batteries

The “shuttle effect” caused by the shuttling of soluble long-chain polysulfides between the anode and cathode electrodes has persistently hindered lithium–sulfur batteries (LSBs) from achieving stable and high-capacity performance. Numerous materials have been explored to mitigate the adverse effects of this phenomenon, among which metal oxides and metal sulfides are regarded as promising solutions due to their strong adsorption capability toward lithium polysulfides (LiPSs). However, the poor electrical conductivity of the metal oxides and sulfides, coupled with their inherent morphological limitations, makes it challenging to sustainably suppress LiPS shuttling. In this study, we designed a heterostructured catalyst composed of a metal oxide–metal sulfide heterostructure integrated with carbon nanotubes (CNTs). This design addresses the low conductivity issue of metal oxides/sulfides while optimizing the material’s morphology, enabling persistent LiPSs adsorption. Furthermore, the composite successfully facilitates three-dimensional (3D) Li₂S deposition. The assembled battery exhibits stable and high-capacity performance, delivering an initial discharge capacity of 622.45 mAh g⁻¹ at 2C and retaining 569.5 mAh g⁻¹ after 350 cycles, demonstrating exceptional cycling stability.