Crystallined Hybrid Carbon Synthesized by Catalytic Carbonization of Biomass and in-situ Growth of Carbon Nanofibers

Crystallined hybrid carbon was synthesized by the catalytic carbonization of biomass (Pinus kesiya sawdust) at 1100 °C and in-situ growth of carbon nanofibers (CNFs) at 750 °C from acetylene. The microstructure of the composite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that highly crystallined carbon composed of well-aligned graphene layers with interlayer spacing of 0.34 nm can be formed by catalytic carbonization of biomass. However, the structure of the in-situ growing CNFs is less-aligned. Based on the results of the investigation, the formation mechanism of the crystallined hybrid carbon was discussed. Owning to synergistic effect of the highly crystallined carbon and the conductive network formed by CNFs, the crystallined hybrid carbon shows 32.6% lower electrical resistivity than biocarbon. When being used as anode material of lithium-ion batteries (LIBs), the crystallined hybrid carbon and the biocarbon have nearly the same first coulombic efficiencies (CEs), however, the former has a discharge capacity of 67% higher than the latter since the second cycle.