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Herringbone carbon nanofibers (CNFs) were efficiently produced by chemical vapor deposition on Ni nanoparticles derived from layered double hydroxide (LDH) precursors. The as-obtained CNFs with a diameter ranging from 40 to 60 nm demonstrated herringbone morphologies when they grew on Ni/Al LDH derived catalysts both in the fixed-bed and fluidized-bed reactor. The Ni/Mg/Al, Ni/Cu/Al, as well as Ni/Mo/Mg/Al catalysts were also effective to grow herringbone CNFs. The diameter and specific surface area of the as-obtained CNFs highly depended on the catalyst composition and the growth temperature. When CNFs were grown at 550 °C on Ni/Al catalyst, the as-obtained products had an outer diameter of ca. 50 nm and a specific surface area of 242 m2 g−1, possessed a discharge capacity of 330 mAh g−1 as the electrode in a two-electrode coin-type cell. With the increase of the surface area, the discharge capacity increased at a rate of 0.90 mAh cm−2, while the initial coulombic efficiency decreased gradually on nanocarbon anodes. This is attributed to the fact that CNFs with higher surface area afford smaller sp2 carbon layer that facilitated more Li ions to extract from the anodes.

The strategy to regularly arrange and join the polycyclic aromatic hydrocarbons of asphalt into graphene was explored. Expanded vermiculite with a multi-layered structure was used to adsorb asphaltene molecules onto its surfaces or into its interstices, and graphene sheets with 8–10 graphene layers and a width of tens of microns were obtained by carbonization of the regularly-arranged asphalt molecules. The formation of graphene layers is ascribed to not only the regular arrangement of asphaltene molecules due to the adsorption by vermiculite layers but also the joining of the asphaltene molecules catalyzed by the Fe-containing vermiculite surfaces. By the preabsorption of melamine on vermiculite, a nitrogen-doped graphene–carbon nanotube hybrid was produced from asphalt. As anodes for Li-ion batteries, the obtained graphene materials exhibited increased capacities and rate performance as compared to the widely-used reduced graphene oxide, indicating that the asphalt-derived graphene materials have a reasonable quality.

Vertically oriented carbon nanosheet (VCNS)–carbon nanotube (CNT) hybrid films with a large area (∼4 cm 2 ) were fabricated on Mo layers by using microwave plasma-assisted chemical vapor deposition technique. The Mo layers, which were deposited on Al 2 O 3 ceramic substrates through electron beam evaporation deposition, were pretreated by a laser-grooving technology (4 lines/mm). The films were characterized by scanning electron microscopy, Raman spectroscopy and field emission I – V measurements. A pure VCNS film was found in the laser-etched area, while in the un-etched area a hybrid film of VCNS–CNT was formed. The growth mechanisms of the films were discussed. Effects of laser-grooving pretreatment on surface morphologies and microstructure of the hybrid films were investigated. Field electron emission results showed a turn on field as low as 1.0 V/μm and a high current density of 3.2 mA/cm 2 at an electric field of 5.8 V/μm. The low threshold field and high emission current density were attributed primarily to the unique shape and small resistivity of the films.

High efficient sulfur cathode materials were constructed by the incorporation of aligned sulfur-coated carbon nanotubes (CNTs) and a polyethylene glycol (PEG) barrier at one end. During the charge and discharge of lithium sulfur batteries, high Li ion storage performance can be achieved on the composite electrode, which was benefited from both the aligned CNT structure and the polymer barrier. Aligned CNT framework afforded high conductivity for electron transportation and ordered pores for lithium ion transportation. Meanwhile, the PEG barrier layer greatly suppressed the shuttle of polysulfides. Therefore, this aligned sulfur-coated CNTs with a PEG barrier showed a high initial discharge capacity of 920 and 1128 mAh g−1 in lithium bis(trifluoromethanesulfonyl)imide/1,3-dioxolane/1,2-dimethoxyethane and electrolyte with LiNO3 additives, respectively. The PEG coated cathode showed high cycle stability that a low degradation with 0.38% per cycle during the 100 cycles at 0.1 C was achieved in LiNO3-free electrolytes. These Li storage performance was superior to the aligned sulfur-coated CNT electrode without PEG barrier.