Nanoconfined VO2 in Hierarchical Mesoporous Carbon Nanotube for High-Performance Lithium–Sulfur Batteries

The application of lithium-sulfur batteries (LSBs) is significantly hindered by the challenges of polysulfide shuttle, insulating properties of sulfur and lithium polysulfide, and volume changes in the sulfur cathode during cycling. To address these issues, we design a novel multifunctional sulfur host composed of highly dispersed VO₂ nanoparticles confined within a mesoporous carbon-coated carbon nanotube matrix (VO₂-mNC@CNT). The cathode based on VO₂-mNC@CNT exhibits significantly improved sulfur redox kinetics and effectively suppresses the shuttle effect. The optimized LSBs exhibit outstanding electrochemical performance, delivering an initial capacity of 1152.6 mAh g^-1 at 0.5 C with an excellent capacity retention of 88.3% after 100 cycles. Moreover, the batteries maintain a reversible capacity of 441.3 mAh g^-1 after 1000 cycles at 1.0 C, corresponding to an ultralow capacity decay rate of merely 0.05% per cycle. These results highlight the great potential of the VO₂-mNC@CNT composite as a high-performance sulfur host for advanced LSBs.