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Single-walled carbon nanotube (SWCNT) double helices were fabricated with directly synthesized FeMoMgAl layered double hydroxide flakes as the catalyst precursor. The as-obtained SWCNT double helices were closely packed, while the screw pitches of the double helices were tunable from 2 to 10 μm. Straight millimeter-length SWCNT yarns can be obtained by further stretching the SWCNT double helices.

Fluffy carbon nanotubes (CNTs), which are cotton-like macroscopic structures, are obtained by simple high-speed shearing of vertically aligned CNT (VACNT) arrays. The fluffy CNTs are composed of CNT bundles with a diameter of several micrometers, and have an extremely low apparent density of 3–10 g/L. A requisite for their formation is the alignment of CNTs in the initial array. The shear between the rotor and the arrays tears the arrays along the axial direction and this results in their dispersion into low density fluffy CNTs.

Carbon nanotube (CNT) forests were obtained from liquefied petroleum gas (LPG) as the carbon source in the floating catalyst process. The CNTs obtained in the forest had a thinner diameter and lower growth rate than those obtained with other carbon sources, which was attributed to the existence of sulfur in the LPG. The use of unpurified LPG provides a controllable way to synthesize a CNT forest at low cost.

Lithium-ion batteries (LIBs) are extensively used in numerous portable devices such as smart-phones and laptops. However, current LIBs based on the conventional intercalation mechanism cannot meet the requirements of the electronics industry and electric vehicles although they are approaching their theoretical capacity. Therefore, it is extremely urgent to seek for systems with higher energy densities. Among various promising candidates, lithium–sulfur (Li–S) batteries with a high theoretical capacity are very attractive. However, the commercial use of Li–S batteries still faces obstacles such as the low electrical conductivity of sulfur and lithium sulfide and the dissolution of polysulfides. The introduction of nanocarbon materials into Li–S batteries sheds light on the efficient utilization of sulfur by improving the conductivity of the composites and restraining the shuttle effect of polysulfides. Here, we give a brief review of recent progress on carbon/sulfur composites, especially carbon nanotube-, graphene- and porous carbon-based hybrids, new insights on the relationships between the structure and the electrochemical performance, and propose some important aspects for the future development of Li–S batteries. [New Carbon Materials 2014, 29(4): 241–264]