Pyrolitic carbon from biomass precursors as anode materials for lithium batteries

Disordered carbonaceous materials were synthesized by the pyrolysis of banana fibers treated with pore-forming substances such as ZnCl₂ and KOH. X-ray diffraction studies indicated a carbon structure with a large number of disorganized single layer carbon sheets. Addition of porogenic agent led to remarkable changes in the structure and morphology of the carbonaceous products. The product obtained with ZnCl₂ treatment gave first-cycle lithium insertion and de-insertion capacities of 3325 and 400 mAh g⁻¹, respectively. Lower capacities only could be realized in the subsequent cycles, although the coulombic efficiency increased upon cycling, which in the 10th cycle was 95%.