A series of porous carbons (PCs) with tunable surface areas were prepared by molten salt (NaCl/KCl) method with the assistance of CaCO 3 . Gas sorption analyses by N 2 and CO 2 show that the usage of CaCO 3 leads to the increasement of in micropores and mesopores, thus enlarging the surface area up to 864 from 425 m 2 g −1 . Besides, numerous micropores (<0.6 nm) inaccessible to N 2 can be detected by CO 2 . Supercapacitive performance for PCs was also investigated in aqueous KOH, H 2 SO 4 and KI-additive (H 2 SO 4 + KI) electrolytes as well. Combining the results of pore-structure analysis, the investigations on the relationship between specific capacitance and pore-size show that the minimum pore entrance for SO 4 2− , K + and I − are 0.4, 0.32 and 0.4 nm, respectively. Considering the naked/solvated ionic sizes of SO 4 2− (0.38/0.58 nm), K + (0.26/0.42 nm) and I − (0.39/0.66 nm), desolvation effect probably occurs in those aqueous electrolytes. Moreover, the effect of oxygen functionalities on the redox reaction was also investigated in this work. It is found that the quinone oxygen species is electrochemically active in both H 2 SO 4 and KI-additive electrolytes. With the addition of KI in electrolyte, the prepared porous carbon-based supercapacitor possesses high specific energy of 55.7 Wh kg −1 .
To investigate the effect of structural properties of fluorinated graphene (FG) on the supercapacitive properties in KI additive electrolyte , the porous structure and surface F element content of FG were adjusted via chemical reduction by hydrazine and heating treatment. Systematically electrochemical measurements show that there is a dramatical increase of specific capacitance (583 F/g) in KI-additive electrolyte due to the pseudocapacitance brought by KI compared with that (17 F/g) in pure H 2 SO 4 electrolyte. Investigation on the relationship between F content and areal capacitance show that small amount of F content, especially for semi-ionic C-F species with better electronic conductivity compared with covalent C-F species, can effectively promote the areal capacitance. With moderate F content and relatively high specific surface area, the assembled symmetric supercapacitor can deliver an energy density of 8.89 Wh kg −1 and exhibits a long cyclic stability.
危险品化学品经营许可证（带存储）