Effects of pre-carbonization on structure and electrochemical performances of amphiphilic carbonaceous material-based activated carbons

摘要

Activated carbons to be used as electrode in electrochemical double-layer capacitors were fabricated using amphiphilic carbonaceous material (ACM) as precursor. To study the significance of functional groups and microcrystalline of the precursor in preparing AC, we applied pre-carbonization upon the ACM under different conditions to control these two parameters in this paper. FTIR and XPS spectra showed functional groups on the precursors decreased as the increase of pre-carbonization temperature. After carbonization at 800°C, the growth of graphitic microcrystallites was noticeable. Porous structure parameters of final ACs inferred that the functional groups on the precursors have a more significant effect than microcrystalline size on formation of mesopores during activation process not only for its role as active sites but also the homogeneous activation profited from the solubility of samples in alkaline solutions. The sample AC0 with almost half mesopores showed the best electrochemical behavior with a specific gravimetric capacitance of 255 F/g at current density of 1000mA/g and kept rectangular shape cyclic voltammetry curve even at scan rate high as 400 mV/s.