Relation of micropores/mesopore ratio on high electrochemical performance of nano-porous carbons

Fluorine-doped microporous carbons (F-MCs) are prepared only by carbonization of poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) without further heteroatom doping process and activation. The effects of the porous features and surface characteristics of F-MCs are investigated as a function of carbonization temperature. Without additional activation, the F-MCs, which have an irregular particle shape, have a high specific surface area (856 m(2) g(-1)) due to micropore formation caused by the release of fluorine groups during carbonization. From the charge/discharge results, the specific capacitance of the F-MCs increase with increasing carbonization temperature, and the specific capacitance (268 F g(-1)) of F-MCs prepared with high carbonization (800 degrees C) is higher than F-MCs (221 F g(-1)) obtained at 600 degrees C. This suggests that the well-developed carbon structure, microporous features (<1 nm), and functional groups (F and O) of F-MCs allow the easy transfer and excellent accessibility of electrolyte ions, resulting in the maximizing of electrochemical performance of PVDF-HFP-based carbons for supercapacitors. (C) 2013 Elsevier B.V. All rights reserved.