Low-temperature synthesis of graphitized nanofibers for reversible lithium-ion insertion/extraction

Graphitized carbon nanofibers are prepared from 2-propanol at 673 K by spray pyrolysis in which dc high voltage is applied to the spray nozzle. A mixture of helical and straight carbon nanofibers is observed, and their diameters are ca. 100-300 nm. The resultant carbon nanofibers show large capacity of around 340 mAh g−1 and high reversibility with little hysteresis after the 2nd cycle in insertion/extraction reactions of lithium-ion, while a large irreversible capacity of 400 mAh g−1 is observed at potentials below 0.9 V in the 1st cycle.