Effect of Carbonization on the Structure and Supercapacitive Performance of Pitch-Based Activated Carbon Fibers

The porous activated carbon fibers (ACFs) were obtained by the anisotropic mesophase pitch carbon fibers carbonized at 450 degrees C through a simple KOH chemical activation method. In order to improve the degree of crystallinity of the ACFs, the as-prepared ACFs were modified by carbonization. The effects of carbonization temperatures on the morphology, crystallinity, pore structure and supercapacitive performances of ACFs were systematically investigated. The ACFs carbonized at 1 200 degrees C (ACFs-1200) electrodes exhibit excellent electrochemical performance with a specific capacity of 204 F.g(-1) at 0.1 A.g(-1) which show a capacity retention of 97.0% after 1 000 cycles. Even at 20 A.g(-1) the electrodes maintain a high specific capacity of 149 F.g(-1) The results show that the ACFs-1200 electrodes deliver ultrahigh conductivity, high rate capacity and exceptional cycle stability compared with the non-carbonized ACFs electrodes.