Preparation and Capacitive Performance of the Anion Intercalation Graphite Materials as Positive Electrode Materials

Microstructure and energy storage performance of the needle coke heated at 1500 and 2800 degrees C were investigated by scanning electron micrograph(SEM), cyclic voltammetry(CV) and charge-discharge methods, and the influence of the degree of graphitization to the performance of graphite was studied. The specific discharge capacity of needle coke sintered at 1500 and 2800 degrees C were 70.1 and 90.6 mA . h/g in organic electrolyte when the current density was controlled at 50 mA/g. The specific capacity was 55 mA . h/g when the current density was raised to 5 A/g. However, the specific capacity of commercialization active carbon was only 35.9 mA . h/g when the current density was controlled at 50 mA/g. The retention of the capacitance after 1000 charge-discharge cycles were 95.7% and 89.2%, respectively, when the current density was controlled at 1 A/g.