Layer-Spacing-Enlarged MoS₂ Superstructural Nanotubes with Further Enhanced Catalysis and Immobilization for Li–S Batteries

A layer-spacing-enlarged MoS₂ nanotube (LE-MoS₂) consisting of hierarchical superstructural nanosheets (−MoS₂–carbon layer–MoS₂−) was fabricated and served as the sulfur host. The (002) lattice plane of LE-MoS₂ is greatly expanded to 1.04 nm and 67.7% higher than that of the conventional 2H-MoS₂. Benefitting from the layer-spacing-enlarged hierarchical superstructure of LE-MoS₂, the catalytic effect on the S_(s)–Li₂S_x (soluble, x > 6)–Li₂S_y (soluble, y > 2)–Li₂S_(s) phase transformation kinetics and immobilizing effect on the soluble Li₂S_y in Li–S batteries are both further enhanced and demonstrated by in situ X-ray adsorption near-edge structure spectroscopy and first-principles calculations. The formation of hierarchical superstructural nanosheets was carefully investigated by customized synchrotron vacuum ultraviolet photoionization mass spectrometry.