Electrochemical exfoliation of graphite in the flame-retarded electrolyte is used for the preparation of novel carbon materials for the first time. Graphitic platelets with submicron thickness are prepared by an electrochemical graphite exfoliation route in the trimethyl phosphate (TMP) based electrolyte. The morphology and size of the graphitic platelets can be controlled by adjusting the reaction temperature and current density. A possible mechanism is proposed for the interesting graphite exfoliation in the TMP-based electrolyte. Compared with common micrometer-scale graphite and graphene nanosheets, this novel graphitic material exhibits different voltage profiles but good rate capability as anode in the Li-ion batteries.