Pyrolysis of hexa(phenyl)benzene derivatives: a molecular approach toward carbonaceous materials for Li-ion storage

Hexa(phenyl)benzene (HPB) and hexakis(p-bromophenyl)benzene (HPB-Br) were submitted to controlled pyrolysis under mild conditions to prepare carbonaceous materials for Li-ion storage. Experiments were performed in evacuated sealed ampoules and different temperatures (in the range 500–600 °C) and heating times (1 upto 5 days) were applied. Pyrolytic products were obtained as black flakes and characterised by elemental analysis, thermogravimetric analysis, UV–vis–NIR and Raman spectroscopies. Scanning electron microscopy exhibited several structures (nanorods, bundles, microspheres) on the surface of the flakes, depending on the precursor and on the pyrolysis procedure. Preliminary electrochemical measurements revealed lithium storage capacities upto 500 mAh g−1.