Abstract: Polyimide derived activated carbon was prepared by carbonization and KOH activation, which was used for electrode material of electric double-layer capacitors. Its pore structure and surface chemical property were studied by DFT and XPS, respectively, and its electrochemical properties were studied by electrochemical methods, such as, charge-discharge of constant current. The results show that both the nitrogen content and the porosity of sample CPI affect its gravimetric capacitance. After activation, the specific areas of sample API reach 1941m²/g, the micropore formed is all less than 2nm. The effect of nitrogen atom can be ignored. Its gravimetric capacitance reach 300F/g with the discharging current density of 50mA/g, and remain 86.1% of its capacitance when the current density reaches 1000mA/g. The results of impedance also show that sample API has good electric double-layer performance which is novel electrode material for electric double layer capacitor.

Key words: polyimide, electric double-layer capacitor, electrochemical performance