Controlled hydrothermal synthesis of 1D nanocarbons by surfactant-templated assembly for use as anodes for rechargeable lithium-ion batteries

Abstract

In this study, we have developed a facile and controllable hydrothermal synthesis assisted by surfactant-templating and subsequent carbonization for low dimensional nanocarbons, particularly 1D rods/fibers. In this synthesis, resorcinol and hexamethylene tetramine (HMT) were used as the monomers and the surfactant Pluronic F127 as the structural directing agent. The nanostructures and morphologies of the as-synthesized carbon can be simply tailored by changing the concentrations of F127 and HMT. The obtained 1D nanocarbon structures with BET surface areas in the range of 570–585 m² g⁻¹, markedly varied in shape from rods to fibers. When using these nanocarbon structures as the anode material for lithium ion batteries, it was found that carbon nanofibers demonstrated good rate performance (a high reversible capacity of 160 mA h g⁻¹ at a current density of 1500 mA g⁻¹ (ca. 4C)), which is much higher than that of the commercial artificial graphite. This high rate capability is attributed to the unique morphology of the carbon nanofibers with an average diameter of ∼45 nm. Such thin and porous carbon fibers allow fast lithium ion transportation.