Preparation of nitrogen-doped pitch-based carbon materials for supercapacitors

摘要

Coal tar pitches (CTP) are used as precursor of electrode material because of their low cost and high carbon yield. In this study, LIP-based activated carbon materials (CACs) with high capacitance for supercapacitors were prepared by doping elemental N with co-carbonization of CTP and melamine. The electrochemical performance and textural characterization of CACs were investigated by constructing a single electrode capacitor in a 6 M KOH electrolyte, N-2 adsorption, scanning electron microscopy, and XPS. Results show that CACs with mass proportion of melamine and CTP being 1:5 possess a surface area of 2573 m(2) g(-1), with mesopore volume accounting for 56% of the total volume. After co-carbonization, N content on the surface of the CACs increased by 134% compared to that of undoped activated carbons. Their capacitance reached up to 228 F g(-1) at a current density of 1 A g(-1). The high electrochemical performance of the CACs is attributed to its additional pseudo-capacitance and high surface area. The specific capacitance still possessed 94.2% retention after 1000 cycles, indicating good cycle stability. (C) 2015 Elsevier B.V. All rights reserved.