An easy and environmentally friendly method was developed for the preparation of a stabilized carbon nanotube-crystalline nanocellulose (CNT-CNC) dispersion and for its deposition to generate self-standing CNT-CNC composite films. The composite films were carbonized at different temperatures of 70 °C, 800 °C, and 1300 °C. Structural and morphological characteristics of the CNT-CNC films were investigated by X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM), which revealed that the sample annealed at 800 °C (CNT-CNC800) formed nano-tree networks of CNTs with a high surface area (1180 m2·g-1) and generated a conductive CNC matrix due to the effective carbonization. The carbonized composite films were applied as anodes for lithium-ion batteries, and the battery performance was evaluated in terms of initial voltage profile, cyclic voltammetry, capacity, cycling stability, and current rate efficiency. Among them, the CNT-CNC800 anode exhibited impressive electrochemical performance by showing a reversible capacity of 443 mAh·g-1 at a current density of 232 mA·g-1 after 120 cycles with the capacity retention of 89% and high rate capability.
Keywords: carbon nanotubes; carbonization; lithium-ion batteries; nanocellulose; self-standing composite anode.