A pulsed capacitive energy storage must provide a high discharge current and a nominal capacity, a long persistence of the charge and a high discharge time constant. A liquid condenser can be used as the storage element in pulsed capacitive energy storage. In this paper, the thermally expanded graphite was chosen as a material of the capacitor plates. Thermally expanded graphite is characterized by a highly developed inner surface. Our studies have shown that the adsorption layer characterized by the high capacity is formed from expanded graphite electrodes. In addition, the paper presents the investigation results of compaction of expanded graphite powders. The methods of forming the electrodes on the basis of expanded graphite powders for energy sources have been considered. Investigations have been carried out on the electrochemical properties of the obtained electrodes. These investigations allow recommending the use of thermally expanded graphite as the electrode material for electrodes of liquid capacitors.